Increasing solar activity could wreak havoc

The sun waking from a deep sleep may not sound like such a bad thing and years ago it might not have been.

However in today's world reliant on technology for the basics of everyday life, increasing levels of solar activity and the flares from the consequent 'space storm' could wreak complete havoc.

Nasa is telling us to prepare for a once in a generation storm which could result in widespread blackouts and leave us without critical communication signals for considerable periods of time.

The overheating of national power grids, mass disruption of air travel and the complete shut down of electronic items, navigation devices and major satellites are just some of the consequences of the sun reaching its maximum power in only a few years time.

As well as this, the bolt of lightning caused by the super storm could bring disastrous consequences for the world emergency service systems, hospital equipment and of course would leave us without our computers, sat navs and ipods.

The worst case scenario would see large parts of the world plunged into darkness for months

Most likely say senior scientists it will last hours and maybe days but this in a world reliant on high tech systems for almost everything we do is likely to have a drastic impact.


from: http://au.news.yahoo.com/a/-/technology/7406476/solar-activity-wreak-havoc

What's a Healthy Weight?

What's a Healthy Weight?

Although nutrition experts still have different ideas about the precise limits of what's a healthy weight, there's a good working criteria based on the ratio of weight to height. This ratio, called the body mass index (or BMI for short),consider the fact that taller people have more tissue than shorter people, and so should weigh more.

Nothing magical happens when you cross from 20.4 to 20.5 or from 31.9 to 32. These are just convenient reference points. Instead, the chances of developing a weight-related health problems increases across the range of weights.Lots of studies that have included more than a 1000 thousands adults have indicated that a body mass index above 25 increases the chances of dying early, mainly from cancer or heart diease, and that a body mass index above 30 dramatically increases the chances. Based on this consistent evidence, a healthy weight is one that equates with a BMI less than 25. By convention, overweight is defined as a BMI of 25 to 29.9, and obesity is defined as a BMI of 30 or higher.

Muscle and bone are more dense than fat, so an athlete or muscular person may have a high BMI, but not be obesity. It's this thing that makes weight gain during adulthood such an important determinant of weight-related health—few adults add muscle and bone after their early twenties, so almost all that added weight is fat rather than muscle. 

Weight loss and carbohydrates

Carbohydrates are very important  to our body, they are also the only fuel source for many vital organs, including the central nervous system, brain  and kidneys. The digestive system decomposes carbohydrates into glucose and the pancreas secretes a hormone(insulin) to help the glucose move from the blood into the cells.

Very low carbohydrate diets
Very low carbohydrate diets are becoming popular again. These diets often contain less than 60g of carbohydrate per day. But they have a high fat content (particularly saturated fat) and restrict fruit, vegetables and high fibre breads and grain,that's why many health professionals don't support it.

Low carb diets restrict healthy food choices
Supporters of very low carbohydrate diets suggest people to consume kilojoules mainly from fat sources and protein. This means limiting cereals, some vegetables and fruit, while eating more meat, fat and dairy foods. Traditional foods eaten on a low carbohydrate diet include bacon, chicken, beef, eggs, fish and non-starchy vegetables, as well as fats such as butter, oils and mayonnaise. Forbidden foods include bread,fruit, grains, starchy vegetables and dairy products other than cream, cheese or butter.

Very low carbohydrate diets is not enough to meet your daily nutritional needs. To be healthy, your daily diet should include more, at least:

• Two cups of milk.
• Four serves of cereals or bread
• Five serves of vegetables
• Two serves of fruit

The safety for long term eating very low in carbohydrates but high in saturated fat is still uncertain. Some experts believe it’s an attack for the heart . Follow-up studies are needed over years to determine the safety of very low carbohydrate diets.

Weight gain comes from eating too many calories
The basic principle of any low carbohydrate diet is that carbohydrates cause weight gain. This is misleading. You gain weight if you consume too many kilojoules (or calories) - it doesn’t matter if they are from carbohydrates, proteins or fats or carbohydrates. The principle of  carbohydrates cause weight gain is misleading.

There’s nothing special about a low carbohydrate diet
Yes,maybe low carbohydrate diets cause you to lose weight because they restrict kilojoules or energy, but it is because the metabolic disturbances to the body,not the diet. This diet starves the body of the nutrients it needs and can cause major metabolic disturbances to the body. There is nothing special about the proportions of carbohydrate to protein - there are just fewer calories consumed in these diets, which causes the weight loss.

Low carb weight loss is mainly water in the short term
The body stores excess glucose as glycogen and converts glycogen back into glucose to use as fuel if there is not enough carbohydrate in the diet. to release one gram of glycogen need 3g water, so the rapid initial weight loss on a low carbohydrate diet is mostly water, not body fat.

When a normal diet is resumed, some muscle tissue is rebuilt, water is restored and weight quickly returns, mostly as fat. This can contribute to the problem effect of dieting called the ‘yoyo’ effect.

Weight loss needs a healthy approach
A diet high in vegetables and fruits,legumes, wholegrains, and low fat dairy products, and moderate in fat and calories, is the best way to lose weight and keep it off.

Vegetarians and people who consume predominantly plant-based diets are generally slimmer and have much lower rates of obesity, cancer and heart disease  than people who eat meat-based diets. This supports current thinking that diets high in unrefined carbohydrates help to prevent overweight and obesity.

Short term side effects of low carbohydrate diets
Within a short period of time, the effects of a very low carbohydrate diet include:

• Nausea
• Constipation
• Dizziness
• Dehydration
• Lethargy
• Loss of appetite
• Bad breath.

Potential long term effects of low carbohydrate diets
The potential effects on health if a very low carbohydrate diet is consumed long term are unknown. However, these diets may be nutritionally inadequate because they contain few vegetables and fruits. They tend to be low in  thiamin, fibre, folate, vitamins A, E and B6, magnesium, calcium, potassium, iron and antioxidant phytochemicals. Such a diet could increase a person’s risk of developing cancer by restricting intakes of antioxidants and fibre from fruits and vegetables.

Very low carbohydrate diets also tend to be high in saturated fat which can contribute to heart disease risk. Diets that are high in protein and fats are associated with abdominal obesity and obesity-related disorders including cancer, diabetes and heart disease.

If the body doesn’t receive enough carbohydrate, it breaks down muscle and other tissue to produce glucose. This causes a build-up of waste products called ‘ketones’. This state, known as ‘ketosis’, is commonly seen in people who are starving, suffering from anorexia nervosa or with untreated insulin-dependent diabetes. Ketones make the blood acidic. Ketosis can be fatal in severe conditions, particularly for pregnant women, their unborn babies and for people with diabetes. There is also evidence that the heart may not be able to function to its full capacity when ketone bodies are its main source of fuel.

A very high protein diet can be dangerous
High protein foods, such as meat, are usually high in saturated fats and cholesterol. Typically these high protein diets contain about 125g protein per day and moderate amounts of carbohydrate. The long term health risks of a diet high in protein include:

• Increased risk of developing gout and gall bladder colic
• High cholesterol, which is associated with a range of conditions including heart disease
• Kidney problems in people with impaired kidney function or diabetes
• Loss of bone mineral content
• Liver problems.

Select carbohydrates, proteins and fats carefully
If you do choose to follow a low carbohydrate diet, do not avoid carbohydrates completely - you need some in your diet to metabolise fat. Choose carbohydrate rich foods that are unrefined or unprocessed, including whole grains and fruit, rather than the more refined and energy-dense forms such as cakes, sweets and soft drinks. Have a variety of vegetables daily.

Select a variety of protein rich foods that are also low in saturated fat, for example:

• Lean cuts of red meat
• Lean chicken and pork
• Fish (including fatty fish).

You could also select protein rich foods that are plant-based, for example:

• Nuts
• Soy products, including tofu
• Legumes such as beans and pulses.

Choose fats from plant sources (such as olives , canola oil,olive oil,  peanut oil,peanuts, soy or soy oil) rather than from animal sources (butter or meat fat).

Ultimately, to avoid weight gain, energy intake should not be more than energy output over a period of time. Avoiding large portion sizes will help keep energy intake in check. For long term weight management, the benefits of regular physical activity cannot be emphasised enough.

Getting more physical activity - 5 quick tips

1. Choose activities you like. Pick activities you enjoy. A lot of different things count as exercise: dancing, walking, gardening, playing basketball. Choose whatever gets you moving.

2. Try a pedometer. Pedometers are cheap and easy to use. Best of all, they help you keep track of how active you are. Build up to 7,000 steps a day—or more.

3. Piece your workout together. You don't need to get all your exercise at one time. Ten minutes morning, noon, and night can give much of the same benefit as 30 minutes all at once.

4. Exercise with a friend. Finding a workout partner can help keep you on track and motivate you to get out the door.

5. Take lunch on the move. Don't spend your lunch time sitting. Grab a quick meal and hit the gym or go for a walk with coworkers.

The Nutrition Source Carbohydrates: Good Carbs Guide the Way

Introduction

We've come a long way from the days when one of the knee-jerk answers to the question "What should I eat?" was "You can't go wrong with carbohydrates." We now know that carbohydrates, the staple of most diets, aren't all good or all bad. Some kinds promote health while others, when eaten often and in large quantities, actually increase the risk for diabetes and coronary heart disease.

The wild popularity of the Atkins, South Beach, and other low-carbohydrate diets led many Americans to believe that carbohydrates are "bad," the source of unflattering flab, and a cause of the obesity epidemic. That's a dangerous oversimplification, on a par with "fat is bad." Easily digested carbohydrates from white bread, white rice, pastries, sugared sodas, and other highly processed foods may, indeed, contribute to weight gain and interfere with weight loss. Whole grains, beans, fruits, vegetables, and other sources of intact carbohydrates do just the opposite—they promote good health.

What Are Carbohydrates?Don't be misled by the blanket pronouncements on the dangers of carbohydrates. They are an important part of a healthy diet. Carbohydrates provide the body with the fuel it needs for physical activity and for proper organ function. The best sources of carbohydrates—fruits, vegetables, and whole grains—deliver essential vitamins and minerals, fiber, and a host of important phytonutrients.

Carbohydrates are found in a wide array of foods—bread, beans, milk, popcorn, potatoes, cookies, spaghetti, soft drinks, corn, and cherry pie. They also come in a variety of forms. The most common and abundant forms are sugars, fibers, and starches.

The basic building block of every carbohydrate is a sugar molecule, a simple union of carbon, hydrogen, and oxygen. Starches and fibers are essentially chains of sugar molecules. Some contain hundreds of sugars. Some chains are straight, others branch wildly.

Carbohydrates were once grouped into two main categories. Simple carbohydrates included sugars such as fruit sugar (fructose), corn or grape sugar (dextrose or glucose), and table sugar (sucrose). Complex carbohydrates included everything made of three or more linked sugars. Complex carbohydrates were thought to be the healthiest to eat, while simple carbohydrates weren't so great. It turns out that the picture is more complicated than that.

The digestive system handles all carbohydrates in much the same way—it breaks them down (or tries to break them down) into single sugar molecules, since only these are small enough to cross into the bloodstream. It also converts most digestible carbohydrates into glucose (also known as blood sugar), because cells are designed to use this as a universal energy source.

When Sugar Management Goes Awry: Insulin and Diabetes Fiber is an exception. It is put together in such a way that it can't be broken down into sugar molecules, and so it passes through the body undigested. Fiber comes in two varieties: soluble fiber dissolves in water, while insoluble fiber does not. Although neither type nourishes the body, they promote health in many ways. Soluble fiber binds to fatty substances in the intestines and carries them out as a waste, thus lowering low-density lipoprotein (LDL, or bad cholesterol). It also helps regulate the body's use of sugars, helping to keep hunger and blood sugar in check. Insoluble fiber helps push food through the intestinal tract, promoting regularity and helping prevent constipation.

When you eat a food containing carbohydrates, the digestive system breaks down the digestible ones into sugar, which then enters the blood. As blood sugar levels rise, special cells in the pancreas churn out more and more insulin, a hormone that signals cells to absorb blood sugar for energy or storage. As cells sponge up blood sugar, its levels in the bloodstream begin to fall. That's when other cells in the pancreas start making glucagon, a hormone that tells the liver to start releasing stored sugar. This interplay of insulin and glucagon ensure that cells throughout the body, and especially in the brain, have a steady supply of blood sugar.

In some people, this cycle doesn't work properly. People with type 1 diabetes (once called insulin-dependent or juvenile diabetes) don't make enough insulin, so their cells can't absorb sugar. People with type 2 diabetes (once called non-insulin-dependent, or adult-onset diabetes) generally start out with a different problem—their cells don't respond well to insulin's "open up for sugar" signal. This condition, known as insulin resistance, causes blood sugar and insulin levels to stay high long after eating. Over time, the heavy demands made on the insulin-making cells wears them out, and insulin production slows, then stops.

Genes, a sedentary lifestyle, being overweight, and a diet rich in processed carbohydrates can each promote insulin resistance. (The combination is far worse.) Data from the Insulin Resistance Atherosclerosis Study suggests that cutting back on refined grains and eating more whole grains in their place can improve insulin sensitivity. (2) As described in "Health Gains from Whole Grains", the benefit of eating whole grains extends far beyond insulin to helping prevent type 2 diabetes, atherosclerosis (the build-up of cholesterol-filled patches that clog and narrow artery walls), heart disease, colorectal cancer, and premature death from noncardiac, noncancer causes.Insulin resistance isn't just a blood sugar problem. It has also been linked with a variety of other problems, including high blood pressure, high levels of triglycerides, low HDL (good) cholesterol, and excess weight. In fact, it travels with these problems so often that the combination has been given the name metabolic syndrome. (1) Alone and as part of the metabolic syndrome, insulin resistance can lead to type 2 diabetes, heart disease, and possibly some cancers.

Carbohydrates and the Glycemic Index

Dividing carbohydrates into simple and complex makes sense on a chemical level. But it doesn't do much to explain what happens to different kinds of carbohydrates inside the body. For example, the starch in white bread and French-fried potatoes clearly qualifies as a complex carbohydrate. Yet the body converts this starch to blood sugar nearly as fast as it processes pure glucose. Fructose (fruit sugar) is a simple carbohydrate, but it has a minimal effect on blood sugar.

A new system, called the glycemic index, aims to classify carbohydrates based on how quickly and how high they boost blood sugar compared to pure glucose.(3) Foods with a high glycemic index, like white bread, cause rapid spikes in blood sugar. Foods with a low glycemic index, like whole oats, are digested more slowly, causing a lower and gentler change in blood sugar. Foods with a score of 70 or higher are defined as having a high glycemic index; those with a score of 55 or below have a low glycemic index.

Diets rich in high-glycemic-index foods, which cause quick and strong increases in blood sugar levels, have been linked to an increased risk for diabetes, (5) heart disease, (6, 7) and overweight, (8, 9,10) and there is preliminary work linking high-glycemic diets to age-related macular degeneration, (11) ovulatory infertility, (12) and colorectal cancer. (13) Foods with a low glycemic index have been shown to help control type 2 diabetes and improve weight loss. Other studies, though, have found that the glycemic index has little effect on weight or health. This sort of flip-flop is part of the normal process of science, and it means that the true value of the glycemic index remains to be determined. In the meantime, eating whole grains, beans, fruits, and vegetables—all foods with a low glycemic index—is indisputably good for many aspects of health.The most comprehensive list of the glycemic index of foods was published in the July 2002, issue of the American Journal of Clinical Nutrition. (4) It included almost 750 foods, ranging from angel food cake to yams. The University of Sydney in Australia maintains an updated searchable database at www.glycemicindex.com that now has almost 1,600 entries.

One of the most important factors that determine a food's glycemic index is how much it has been processed. Milling and grinding removes the fiber-rich outer bran and the vitamin- and mineral-rich inner germ, leaving mostly the starchy endosperm. (See the sidebar, Nutrition In-Depth, for more information on what affects a food's glycemic index.)

One thing that a food's glycemic index does not tell us is how much digestible carbohydrate it delivers. Take watermelon as an example. The sweet-tasting fruit has a very high glycemic index. But a slice of watermelon has only a small amount of carbohydrate per serving (as the name suggests, watermelon is made up mostly of water). That's why researchers developed a related way to classify foods that takes into account both the amount of carbohydrate in the food and the impact of that carbohydrate on blood sugar levels. This measure is called the glycemic load. (14, 15) A food's glycemic load is determined by multiplying its glycemic index by the amount of carbohydrate it contains. In general, a glycemic load of 20 or more is high, 11 to 19 is medium, and 10 or under is low.

You can't use the glycemic index to rule your dietary choices. For example, a Snickers bar has a glycemic index of 41, marking it as a low glycemic index food. But it is far from a health food. Instead, use it as a general guide. Whenever possible, replace highly processed grains, cereals, and sugars with minimally processed whole grain products. And only eat potatoes—once on the list of preferred complex carbohydrates—occasionally because of their high glycemic index and glycemic load. 

Good Carbs, not No Carbs

Some popular diets treat carbohydrates as if they are evil, the root of all body fat and excess weight. That was certainly true for the original Atkins diet, which popularized the no-carb approach to dieting. And there is some evidence that a low-carbohydrate diet may help people lose weight more quickly than a low-fat diet, although so far, that evidence is short term.

In two short, head-to-head trials, (16, 17) low-carb approaches worked better than low-fat diets. A later year-long study, published in 2007 in the Journal of the American Medical Association, showed the same thing. In this study, overweight, premenopausal women went on one of four diets: Atkins, Zone, Ornish, or LEARN, a standard low-fat, moderately high-carbohydrate diet. The women in all four groups steadily lost weight for the first six months, with the most rapid weight loss occurring among the Atkins dieters. After that, most of the women started to regain weight. At the end of a year, it looked as though the women in the Atkins group had lost the most weight, about 10 pounds, compared with a loss of almost 6 pounds for the LEARN group, 5 for the Ornish group, and 3.5 for the Zone group. (18) Levels of harmful LDL, protective HDL, and other blood lipids were at least as good among women on the Atkins diet as among those on the low-fat diet.

If you read the fine print of the study, though, it turns out that few of the women actually stuck with their assigned diets. Those on the Atkins diet were supposed to limit their carbohydrate intake to 50 grams a day, but they took in almost triple that amount. The Ornish dieters were supposed to limit their fat intake to under 10 percent of their daily calories, but they got about 30 percent from fat. There were similar deviations for the Zone and LEARN groups. What this and other diet comparisons tell us is that sticking with a diet is more important than the diet itself.

No one knows the long-term effects of eating little or no carbohydrates. Equally worrisome is the inclusion of unhealthy fats in some of these diets.

If you want to go the lower carb route, try to include some fruits, vegetables, and whole grain carbohydrates every day. They contain a host of vitamins, minerals, and phytonutrients that are essential for good health and that you can't get out of a supplement bottle. And do your heart a favor by choosing healthy fats and proteins to go along with those healthy carbohydrates: A 20-year prospective study of 82,802 women looked at the relationship between lower carbohydrate diets and heart disease; a subsequent study looked at lower carbohydrate diets and risk of diabetes. Women who ate low-carbohydrate diets that were high in vegetable sources of fat or protein had a 30 percent lower risk of heart disease (7) and a modestly lower risk of type 2 diabetes, (19) compared to women who ate high-carbohydrate, low-fat diets. But women who ate low-carbohydrate diets that were high in animal fats or proteins did not have a reduced risk of heart disease or diabetes.(7, 19) 

Adding Good Carbohydrates

For optimal health, get your grains intact from foods such as whole wheat bread, brown rice, whole grain pasta, and other possibly unfamiliar grains like quinoa, whole oats, and bulgur. Not only will these foods help protect you against a range of chronic diseases, they can also please your palate and your eyes.

Until recently, you could only get whole-grain products in organic or non-traditional stores. Today they are popping up in more and more mainstream grocery stores. Here are some suggestions for adding more good carbohydrates to your diet:

Try brown rice with a twist: Check out this recipe for Spicy Coconut Rice with Limes, courtesy of Harvard University Dining Services. 

• Start the day with whole grains. If you're partial to hot cereals, try old-fashioned or steel-cut oats. If you're a cold cereal person, look for one that lists whole wheat, whole oats, or other whole grain first on the ingredient list.
• Use whole grain breads for lunch or snacks.Check the label to make sure that whole wheat or another whole grain is the first ingredient listed.
• Bag the potatoes. Instead, try brown rice or even "newer" grains like bulgur, wheat berries, millet, or hulled barley with your dinner.
• Pick up some whole wheat pasta. If the whole grain products are too chewy for you, look for those that are made with half whole-wheat flour and half white flour. 
• Bring on the beans. Beans are an excellent source of slowly digested carbohydrates as well as a great source of protein.

References

1. Johnson LW, Weinstock RS. The metabolic syndrome: concepts and controversy. Mayo Clinic Proceedings. 2006; 81:1615–20. 

 2. Liese AD, Roach AK, Sparks KC, Marquart L, D'Agostino RB, Jr., Mayer-Davis EJ. Whole-grain intake and insulin sensitivity: the Insulin Resistance Atherosclerosis Study. American Journal of Clinical Nutrition. 2003; 78:965–71. 

3. Ludwig DS. Clinical update: the low-glycaemic-index diet. Lancet. 2007; 369:890–2. 

4. Foster-Powell K, Holt SH, Brand-Miller JC. International table of glycemic index and glycemic load values: 2002. American Journal of Clinical Nutrition. 2002; 76:5–56. 

5. de Munter JS, Hu FB, Spiegelman D, Franz M, van Dam RM. Whole grain, bran, and germ intake and risk of type 2 diabetes: a prospective cohort study and systematic review. PLoS Med. 2007; 4:e261. 

6. Beulens JW, de Bruijne LM, Stolk RP, et al. High dietary glycemic load and glycemic index increase risk of cardiovascular disease among middle-aged women: a population-based follow-up study. Journal of the American College of Cardiology. 2007; 50:14–21. 

7. Halton TL, Willett WC, Liu S, et al. Low-carbohydrate-diet score and the risk of coronary heart disease in women. New England Journal of Medicine. 2006; 355:1991–2002. 

8. Anderson JW, Randles KM, Kendall CW, Jenkins DJ. Carbohydrate and fiber recommendations for individuals with diabetes: a quantitative assessment and meta-analysis of the evidence. Journal of the American College of Nutrition. 2004; 23:5–17. 

9. Ebbeling CB, Leidig MM, Feldman HA, Lovesky MM, Ludwig DS. Effects of a low-glycemic load vs low-fat diet in obese young adults: a randomized trial. JAMA. 2007; 297:2092–102. 

10. Maki KC, Rains TM, Kaden VN, Raneri KR, Davidson MH. Effects of a reduced-glycemic-load diet on body weight, body composition, and cardiovascular disease risk markers in overweight and obese adults. American Journal of Clinical Nutrition. 2007; 85:724–34. 

11. Chiu CJ, Hubbard LD, Armstrong J, et al. Dietary glycemic index and carbohydrate in relation to early age-related macular degeneration. American Journal of Clinical Nutrition.2006; 83:880–6. 

12. Chavarro JE, Rich-Edwards JW, Rosner BA, Willett WC. A prospective study of dietary carbohydrate quantity and quality in relation to risk of ovulatory infertility. European Journal of Clinical Nutrition. 2007. 

13. Strayer L, Jacobs DR, Jr., Schairer C, Schatzkin A, Flood A. Dietary carbohydrate, glycemic index, and glycemic load and the risk of colorectal cancer in the BCDDP cohort.Cancer Causes and Control. 2007; 18:853–63. 

14. Liu S, Willett WC. Dietary glycemic load and atherothrombotic risk. Curr Atheroscler Rep. 2002; 4:454–61. 

15. Willett W, Manson J, Liu S. Glycemic index, glycemic load, and risk of type 2 diabetes.American Journal of Clinical Nutrition. 2002; 76:274S–80S. 

16. Foster GD, Wyatt HR, Hill JO, et al. A randomized trial of a low-carbohydrate diet for obesity. New England Journal of Medicine. 2003; 348:2082–90. 

17. Samaha FF, Iqbal N, Seshadri P, et al. A low-carbohydrate as compared with a low-fat diet in severe obesity. New England Journal of Medicine. 2003; 348:2074–81. 

18. Gardner CD, Kiazand A, Alhassan S, et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial. JAMA. 2007; 297:969–77. 

19. Halton TL, Liu S, Manson JE, Hu FB. Low-carbohydrate-diet score and risk of type 2 diabetes in women. Am J Clin Nutr. 2008;87:339-46.   

The Nutrition Source Food Pyramids: What Should You Really Eat?

Introduction

More than a decade and a half ago, the U.S. Department of Agriculture (USDA) created a powerful and enduring icon: the Food Guide Pyramid. This simple illustration conveyed in a flash what the USDA said were the elements of a healthy diet. The Pyramid was taught in schools, appeared in countless media articles and brochures, and was plastered on cereal boxes and food labels.

With much fanfare, in 2005, the USDA retired the old Food Guide Pyramid and replaced it with MyPyramid, a new symbol and "interactive food guidance system." The new symbol is basically the old Pyramid turned on its side.Tragically, the information embodied in this pyramid didn't point the way to healthy eating. Why not? Its blueprint was based on shaky scientific evidence, and it barely changed over the years to reflect major advances in our understanding of the connection between diet and health.

The good news is that this dismantles and buries the flawed Pyramid. The bad news is that the new symbol doesn't convey enough information to help you make informed choices about your diet and long-term health. And it continues to recommend foods that aren't essential to good health, and may even be detrimental in the quantities included in MyPyramid.

As an alternative to the USDA's flawed pyramid, faculty members at the Harvard School of Public Health built the Healthy Eating Pyramid. It resembles the USDA's in shape only. The Healthy Eating Pyramid takes into consideration, and puts into perspective, the wealth of research conducted during the last 15 years that has reshaped the definition of healthy eating.

Pyramid Building

In the children's book Who Built the Pyramid?, (1) different people take credit for building the once-grand pyramid of Senwosret. King Senwosret, of course, claims the honor. But so does his architect, the quarry master, the stonecutters, slaves, and the boys who carried water to the workers.

The USDA's MyPyramid also had many builders. Some are obvious—USDA scientists, nutrition experts, staff members, and consultants. Others aren't. Intense lobbying efforts from a variety of food industries also helped shape the pyramid.

In theory, the USDA pyramid should reflect the nutrition advice assembled in the Dietary Guidelines for Americans. According to the USDA, the guidelines "provide authoritative advice for people two years and older about how good dietary habits can promote health and reduce risk for major chronic diseases."

This document, which by law must be revised every five years, aims to offer sound nutrition advice that corresponds to the latest scientific research; indeed, on April 10, 2008, the USDA and the U.S. Department of Health and Human Services announced plansto form the advisory committee for the 2010 version of the guidelines. The panel assembled to create the guidelines usually generates 100 or so pages of dense nutrition-speak. This document is translated into a reader friendly brochure aimed at helping the average person choose a balanced and healthy diet. Of far greater importance, the Dietary Guidelines for Americans set the standards for all federal nutrition programs, including the school lunch program, and helps determine what food products Americans buy. In other words, the guidelines influence how billions of dollars are spent each year. So even minor changes can hurt or help a food industry.

According to federal regulations, the panel that writes the dietary guidelines must include nutrition experts who are leaders in pediatrics, obesity, cardiovascular disease, and public health. Selecting the panelists is no easy task, and is subject to intense lobbying from organizations such as the National Dairy Council, United Fresh Fruit and Vegetable Association, Soft Drink Association, American Meat Institute, National Cattlemen's Beef Association, and Wheat Foods Council. (2)

Dietary Guidelines 2005: Two Steps Forward, One Step Back

Released in early January 2005, the Dietary Guidelines for Americans 2005 continues to reflect the tense interplay of science and the powerful food industry. Several of the recommendations in the current version represent important steps in the right direction:

• The current guidelines emphasize the importance of controlling weight, which was not adequately addressed in previous versions. And they continue to stress the importance of physical activity.
• The recommendation on dietary fats makes a clear break from the past, when all fats were considered bad. The guidelines now emphasize that intake of trans fats should be as low as possible and that saturated fat should be limited. There is no longer an artificially low cap on fat intake. The latest advice recommends getting between 20 and 35 percent of daily calories from fats and recognizes the potential health benefits of monounsaturated and polyunsaturated fats.
• Instead of emphasizing "complex carbohydrates," a term used in the past that has little biological meaning, the new guidelines urge Americans to limit sugar intake and they stress the benefits of whole grains.

Others remain mired in the past:

• The guidelines suggest that it is fine to consume half of our grains as refined starch. That's a shame, since refined starches, such as white bread and white rice, behave like sugar. They add empty calories, have adverse metabolic effects, and increase the risks of diabetes and heart disease.
• In terms of protein, the guidelines continue to lump together red meat, poultry, fish, and beans (including soy products). They ask us to judge these protein sources by their total fat content, and "make choices that are lean, low-fat, or fat-free." This ignores the evidence that these foods have different types of fats. It also overlooks mounting evidence that replacing red meat with a combination of fish, poultry, beans, and nuts offers numerous health benefits.
• The recommendation to drink three glasses of low-fat milk or eat three servings of other dairy products per day to prevent osteoporosis is another step in the wrong direction. Of all the recommendations, this one represents the most radical change from current dietary patterns. Three glasses of low-fat milk a day amounts to more than 300 extra calories a day. This is a real issue for the millions of Americans who are trying to control their weight. What's more, millions of Americans are lactose intolerant, and even small amounts of milk or dairy products give them stomachaches, gas, or other problems. This recommendation ignores the lack of evidence for a link between consumption of dairy products and prevention of osteoporosis. It also ignores the possible increases in risk of ovarian cancer and prostate cancer associated with dairy products.

The USDA Pyramid, Brick by Brick

Distilling nutrition advice into a pyramid was a stroke of genius. The shape immediately suggests that some foods are good and should be eaten often, and that others aren't so good and should be eaten only occasionally. The layers represent major food groups that contribute to the total diet. MyPyramid tries to do this in an abstract way, and fails.

Six swaths of color sweep from the apex of MyPyramid to the base: orange for grains, green for vegetables, red for fruits, a teeny band of yellow for oils, blue for milk, and purple for meat and beans. Each stripe starts out as the same size, but they don't end that way at the base. The widths suggest how much food a person should choose from each group. A band of stairs running up the side of the Pyramid, with a little stick figure chugging up it, serves as a reminder of the importance of physical activity.

MyPyramid contains no text. According to the USDA, it was "designed to be simple," and details are at MyPyramid.gov. Unless you've taken the time to become familiar with the Pyramid, though, you have no idea what it means. Relying on the Web site to provide key information—like what the color stripes stand for and what the best choices are in each food group—guarantees that the millions of Americans without access to a computer or the Internet will have trouble getting these essential facts.

The USDA also chose not to put recommended numbers of servings on the new Pyramid because these differ from individual to individual according to weight, gender, activity level and age. Instead, it offers personalized Pyramids at MyPyramid.gov.

Building a Better Pyramid

If the only goal of MyPyramid is to give us the best possible advice for healthy eating, then it should be grounded in the evidence and be independent of business.

Instead of waiting for this to happen, nutrition experts from the Harvard School of Public Health created the Healthy Eating Pyramid, and updated it in 2008. The Healthy Eating Pyramid is based on the best available scientific evidence about the links between diet and health. This new pyramid fixes fundamental flaws in the USDA pyramid and offers sound information to help people make better choices about what to eat. (View a larger PDFimage of the new pyramid, in a separate window.)

The Healthy Eating Pyramid sits on a foundation of daily exercise and weight control. Why? These two related elements strongly influence your chances of staying healthy. They also affect what you eat and how your food affects you.

The other bricks of the Healthy Eating Pyramid include the following: Exercise and weight control are also linked through the simple rule of energy balance: Weight change = calories in – calories out. If you burn as many calories as you take in each day, there's nothing left over for storage in fat cells, and weight remains the same. Eat more than you burn, though, and you end up adding fat and pounds. Regular exercise can help you control your weight, and it is key part of any weight-loss effort.

Whole Grains

The body needs carbohydrates mainly for energy. The best sources of carbohydrates are whole grains such as oatmeal, whole wheat bread, and brown rice. They deliver the outer (bran) and inner (germ) layers along with energy-rich starch. The body can't digest whole grains as quickly as it can highly processed carbohydrates such as white flour. This keeps blood sugar and insulin levels from rising, then falling, too quickly. Better control of blood sugar and insulin can keep hunger at bay and may prevent the development of type 2 diabetes. Plus, a growing body of research suggests that eating a diet rich in whole grains may also protect against heart disease.

Healthy Fats and Oils

Surprised that the Healthy Eating Pyramid puts some fats near the base, indicating they are okay to eat? Although this recommendation seems to go against conventional wisdom, it's exactly in line with the evidence and with common eating habits. The average American gets one-third or more of his or her daily calories from fats, so placing them near the foundation of the pyramid makes sense. Note, though, that it specifically mentions healthy fats and oils, not all types of fat. Good sources of healthy unsaturated fats include olive, canola, soy, corn, sunflower, peanut, and other vegetable oils, trans fat-free margarines, nuts, seeds, avocadoes, and fatty fish such as salmon. These healthy fats not only improve cholesterol levels (when eaten in place of highly processed carbohydrates) but can also protect the heart from sudden and potentially deadly rhythm problems.

Vegetables and Fruits

A diet rich in vegetables and fruits has bountiful benefits. Among them: It can decrease the chances of having a heart attack or stroke; possibly protect against some types of cancers; lower blood pressure; help you avoid the painful intestinal ailment called diverticulitis; guard against cataract and macular degeneration, the major causes of vision loss among people over age 65; and add variety to your diet and wake up your palate.

Nuts, Seeds, Beans, and Tofu

These plant foods are excellent sources of protein, fiber, vitamins, and minerals. Beans include black beans, navy beans, garbanzos, lentils, and other beans that are usually sold dried. Many kinds of nuts contain healthy fats, and packages of some varieties (almonds, walnuts, pecans, peanuts, hazelnuts, and pistachios) can now even carry a label saying they're good for your heart.

Fish, Poultry, and Eggs

These foods are also important sources of protein. A wealth of research suggests that eating fish can reduce the risk of heart disease, since fish is rich in heart-healthy omega-3 fats. Chicken and turkey are also good sources of protein and can be low in saturated fat. Eggs, which have long been demonized because they contain fairly high levels of cholesterol, aren't as bad as they've been cracked up to be. In fact, an egg is a much better breakfast than a doughnut cooked in an oil rich in trans fats or a bagel made from refined flour. People with diabetes or heart disease, however, should limit their egg yolk consumption to no more than 3 a week. But egg whites are very high in protein and are a fine substitute for whole eggs in omelets and baking.

Dairy (1 to 2 Servings Per Day) or Vitamin D/Calcium Supplements

Building bone and keeping it strong takes calcium, vitamin D, exercise, and a whole lot more. Dairy products have traditionally been Americans' main source of calcium and, through fortification, vitamin D. But most people need at least 1,000 IU of vitamin D per day, far more than the 100 IU supplied by a glass of fortified milk. (See the multivitamins section, below, for more information on vitamin D needs.) And there are other healthier ways to get calcium than from milk and cheese, which can contain a lot of saturated fat. Three glasses of whole milk, for example, contains as much saturated fat as 13 strips of cooked bacon. If you enjoy dairy foods, try to stick mainly with no-fat or low-fat products. If you don't like dairy products, taking a vitamin D and calcium supplement offers an easy and inexpensive way to meet your daily vitamin D and calcium needs.

Use Sparingly: Red Meat and Butter

These sit at the top of the Healthy Eating Pyramid because they contain lots of saturated fat. Eating a lot of red meat may also increase your risk of colon cancer. If you eat red meat every day, switching to fish , chicken, or beans several times a week can improve cholesterol levels. So can switching from butter to olive oil. And eating fish has other benefits for the heart.

Use Sparingly: Refined Grains—White Bread, Rice, and Pasta; Potatoes; Sugary Drinks and Sweets; Salt

Why are these all-American staples at the top, rather than the bottom, of the Healthy Eating Pyramid? White bread, white rice, white pasta, other refined grains, potatoes,sugary drinks, and sweets can cause fast and furious increases in blood sugar that can lead to weight gain, diabetes, heart disease, and other chronic disorders. Whole grain carbohydrates cause slower, steadier increases in blood sugar that don't overwhelm the body's ability to handle carbohydrate. The salt shaker is a new addition to the "Use Sparingly" tip of the Healthy Eating Pyramid, one that's based on extensive research linking high-sodium diets to increased risk of heart attack and stroke.

Multivitamin with Extra Vitamin D (For Most People)

A daily multivitamin, multimineral supplement offers a kind of nutritional backup, especially when it includes some extra vitamin D. While a multivitamin can't in any way replace healthy eating, or make up for unhealthy eating, it can fill in the nutrient holes that may sometimes affect even the most careful eaters. You don't need an expensive name-brand or designer vitamin. A standard, store-brand, RDA-level one is fine for most nutrients—except vitamin D. In addition to its bone-health benefits, there's growing evidence that getting some extra vitamin D can help lower the risk of colon and breast cancer. Aim for getting at least 1,000 IU of vitamin D per day; multiple vitamins are now available with this amount. (Many people, especially those who spend the winter in the northern U.S. or have darker skin, will need extra vitamin D, often a total of 3,000 to 4,000 IU per day, to bring their blood levels up to an adequate range. If you are unsure, ask your physician to check your blood level.) Look for a multivitamin that meets the requirements of the USP (U.S. Pharmacopeia), an organization that sets standards for drugs and supplements.

Optional: Alcohol in Moderation (Not for Everyone)

Scores of studies suggest that having an alcoholic drink a day lowers the risk of heart disease. Moderation is clearly important, since alcohol has risks as well as benefits. For men, a good balance point is one to two drinks a day; in general, however, the risks of drinking, even in moderation, exceed benefits until middle age. For women, it's at most one drink a day; women should avoid alcohol during pregnancy. 

Forget about Numbers and Focus on Quality

You'll notice that the Healthy Eating Pyramid does not give specific advice about the numbers of cups or ounces to have each day of specific foods. That's because it's not meant to be a rigid road map, and the amounts can vary depending on your body size and physical activity. It's a simple, general, flexible guide to how you should eat when you eat.

There's just one basic guideline to remember: A healthy diet includes more foods from the base of the pyramid than from the higher levels of the pyramid. Within this guideline, however, there's plenty of flexibility for different styles of eating and different food choices. A vegetarian can follow the Healthy Eating Pyramid by emphasizing nuts, beans, and other plant sources of protein, and choosing non-dairy sources of calcium and vitamin D; someone who eats animal products can choose fish or chicken for protein, with occasional red meat.

Choosing a variety of fresh, whole foods from all the food groups below the "Use Sparingly" category in the Healthy Eating Pyramid will ensure that you get the nutrients you need. It will also dramatically lower your salt intake, since most of the salt in the U.S. diet lurks in processed food—canned soups, frozen dinners, deli meats, snack chips, and the like.

Perhaps the only foods that are truly off-limits are foods that contain trans fat from partially hydrogenated oils. Luckily, in the U.S. and Canada, trans fats must be listed on nutrition labels. More and more food manufacturers, restaurants, and even entire communities are going trans fat-free, making it easier to avoid this health-damaging type of fat.

Other Alternatives

The Healthy Eating Pyramid summarizes the best dietary information available today. It isn't set in stone, though, because nutrition researchers will undoubtedly turn up new information in the years ahead. The Healthy Eating Pyramid will change to reflect important new evidence.

This isn't the only alternative to the USDA's MyPyramid. The Asian, Latin, Mediterranean, and vegetarian pyramids promoted by Oldways Preservation and Exchange Trust are also good, evidence-based guides for healthy eating. The Healthy Eating Pyramid takes advantage of even more extensive research and offers a broader guide that is not based on a specific culture. The original Healthy Eating Pyramid is described in greater detail inEat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating, by Walter C. Willett, M.D. (the Fredrick John Stare Professor of Epidemiology and Nutrition in the Departments of Nutrition and Epidemiology at Harvard School of Public Health) with Patrick J. Skerrett (published by Free Press, 2005).

Failing the Test

Back in the 1990s, the USDA's Center for Nutrition Policy and Promotion created the Healthy Eating Index "to measure how well American diets conform to recommended healthy eating patterns." (3) In its original form, this score sheet used five elements from the longstanding USDA Food Guide Pyramid (number of daily servings of grains, vegetables, fruits, meat, and dairy products) and five from the 1995 Dietary Guidelines for Americans (total fat in the diet, percentage of calories from saturated fat, cholesterol intake, sodium intake, and variety of the diet). A score of 100 meant following the federal recommendations to the letter while a score of 0 meant totally ignoring them. (The USDA has since updated the score sheet to reflect the Dietary Guidelines for Americans 2005.)

To see how well the principles embodied in the Healthy Eating Pyramid stacked up against the government's advice, Harvard School of Public Health researchers created an Alternate Healthy Eating Index with a scoring system similar to the USDA's index. They then compared the two indexes, using information about daily diets collected from more than 100,000 female nurses and male health professionals taking part in two long-term studies.

Men who scored highest on the USDA's original Healthy Eating Index (meaning their diets most closely followed federal recommendations) reduced their overall risk of developing heart disease, cancer, or other chronic disease by 11 percent over 8 to 12 years of follow-up compared to those who scored lowest. Women who most closely followed the government's recommendations were only 3 percent less likely to have developed a chronic disease. (4)

In comparison, scores on the Alternate Healthy Eating Index did appear to correlate more closely with disease in both sexes. Men with high scores (those whose diets most closely followed the guidelines in the Healthy Eating Pyramid) were 20 percent less likely to have developed a major chronic disease than those with low scores. Women with high scores lowered their overall risk by 11 percent. Men whose diets most closely followed the Healthy Eating Pyramid lowered their risk of cardiovascular disease by almost 40 percent; women with high scores lowered their risk by almost 30 percent.

"The new USDA dietary pyramid is a lost opportunity to help Americans make informed choices about diet and long-term health," says Dr. Willett. "It's clear that we need to rebuild the pyramid from the ground up, not just tip it on its side and dress it up with new colors. Every American deserves it."

References

1. Hooper M, Heighway-Bury R. Who Built the Pyramid? Cambridge, Mass.: Candlewick Press, 2001.

2. Abboud L. Expect a food fight as U.S. sets to revise diet guidelines. Wall Street Journal: August 8, 2003, B1.

3. U.S. Department of Agriculture, Center for Nutrition Policy and Promotion. The Healthy Eating Index. 1995. Accessed on 18 April 2007.

4. McCullough ML, Feskanich D, Stampfer MJ, et al. Diet quality and major chronic disease risk in men and women: moving toward improved dietary guidance. Am J Clin Nutr. 2002; 76:1261-71.