The conventional food pyramids promote refined carbohydrates, 4-6 servings of animal products daily and discourage all fat consumption. In contrast the Healthy Eating Pyramid emphasises exercise, weight control, whole plant foods and good fats, and makes animal products optional. The Healthy Eating Pyramid illustrates Walter Willett's seven principal dietary recommendations, which are:

• Maintain a healthy weight. Studies show that the healthiest range for body weight is when the body mass index (BMI) is about 17 to 22. BMI is calculated by dividing one's weight (in kilograms) by the square of one's height (in metres), that is to say: BMI = W/H². This range of healthy weight is lower than has often been recommended but is justified at the top end by the observation that the risk of developing diabetes and other diseases rises significantly for BMI values greater than 22-23^5,6. The low end is based on the finding that among women who had never smoked, those with a BMI of less than 19 had the lowest death rate compared to women with higher BMI values ⁷. Interestingly, non-meat-eaters are on average significantly thinner than meat-eaters⁸. Eating in moderation and exercising are the are the keys to weight control. Exercise builds muscle bulk and thus increases the basal metabolic rate, making it easier to control one's weight. Increased muscle mass also speeds glucose removal from the blood following a meal thus reducing the stress on the pancreas and hence reducing the risk of developing diabetes. A nice side-effect is that you look more attractive when thinner and fitter.
• Eat good fats and avoid bad fats. Good fats are the oils found in nuts, seeds, grains and fish. These are low in saturated fat (the bad fat) and high in the unsaturated fats necessary for good health. Good fats should contribute a significant proportion of total daily calories, say 30 to 45%. To ensure that sufficient of the essential good fat alpha-linolenic acid is consumed, canola oil, flaxseed (linseed), soya oil or walnuts or should be consumed regularly. Avoid saturated fats (animal fats and tropical oils) to minimise the risk of heart disease⁹. And especially avoid hydrogenated vegetable oils since these contain the even the more dangerous trans-saturated fats. Trans-saturated fats are mainly found in margarines and commercial baked goods.
• Eat whole-grain carbohydrates. These are more nutritious than refined carbohydrates and, being more slowly digested, place less stress on pancreatic insulin production. Sources of wholegrain carbohydrates include wholemeal bread, pasta made from whole wheat, brown rice, rolled oats (porridge), pearl barley and amaranth. Avoid white bread, baked goods and pasta made with white flour.
• Avoid red meat as a protein source and emphasise plant proteins. Red meat consumption is linked to a variety of chronic diseases^9-13 and animal protein consumption increases the risk of hip fracture¹⁴. Vegetarians are more insulin sensitive and have enhanced glucose disposal compared to meat-eaters¹⁵. Additionally, animal proteins are usually packaged with saturated fat and cholesterol whereas plant proteins are usually associated with unsaturated fats (coconuts are the main exception). Further, plant proteins are more efficient to produce. The iron content of red meat is often used to promote its consumption but in fact vegetables compare well to red meat when iron content is expressed per calorie content. For example broad beans contain 26mg of iron per 1000 kcal whereas lean porterhouse steak contains only 10mg/1000kcal.
• Eat plenty of vegetables and fruits. Note that potatoes are not included as a vegetable because they are so starchy and rapidly digested. Studies show that little health benefit accrues from consuming potatoes, whereas other vegetables, especially dark green leafy vegetables, and fruit are clearly beneficial. A diet high in fruits and vegetables lowers blood pressure and cholesterol and reduces the risk of cancer.
• Consume alcohol (in moderation). One drink (about 10 grams of alcohol) a day for women and one to two drinks a day for men reduces the risk of heart disease in older omnivores. However in the young, during pregnancy and in the presence of certain diseases, the risks probably out-weigh the benefits. Non-meat-eaters though, because they are at a lower risk of heart disease than omnivores ⁴, probably have less to gain from alcohol consumption and might well choose not to consume it.
• Take a multivitamin daily. There is preliminary evidence that the optimal intake of some vitamins, for example folate, is higher than is easily obtained from food (whether the diet includes meat or animal products or not) and in any case it is not always convenient to eat an ideal diet. Hence this recommendation is insurance against any inadvertent deficiencies and will supply the vitamin B₁₂ that vegans need. For an excellent discussion of why vegans need B₁₂ and how much see Homocysteine and Health. Vegans who work indoors will probably have a need for vitamin D too. Note though that vitamin supplements are not a substitute for eating lots of vegetables and fruit and that high doses may be dangerous.

Indeed, Eat, Drink and be Healthy recommends that adults do not drink milk. Dairy products are optional because epidemiological research finds no evidence that high calcium intakes reduce the risk of fracturing bones^16,17. Despite the impression dairy companies would like to give, hip fracture rates, for example, actually tend to be higher in countries with higher calcium intakes, not lower ¹⁸. Further, research suggests a link between milk consumption and risk of prostate cancer ¹⁹. Exercise is a better way to try to strengthen bones. Also, avoid animal protein¹⁵, eat green vegetables (for vitamin K) and get enough vitamin D (from sunlight or supplements).

Healthy diet pyramids have been published previously, such as the Loma Linda University Department of Nutrition's Vegetarian Food Guide and the Oldways Preservation and Exchange Trust's traditional healthy diet pyramids. The Healthy Eating Pyramid proposed by Professor Willett differs from these earlier healthy pyramids in suggesting that fats (unsaturated of course) play a more prominent part in the diet. The earlier pyramids gave fats a relatively minor role compared to whole grains, legumes, fruit and vegetables. The changed emphasis has come about firstly because a high proportion of unsaturated fat in the diet appears not to be harmful, secondly because of concern that a high proportion of carbohydrate in the diet will place greater demands on insulin production (and thus may lead to diabetes) and thirdly because a high carbohydrate diet tends to raise plasma triglycerides, a risk factor for heart disease. Nuts figure prominently because of their clear health benefits.

The type of diet described by the Healthy Eating Pyramid really does seem to be healthier than the currently conventional Western diet since a Mediterranean diet similar to the Healthy Eating Pyramid was trialed in the Lyon Diet Heart Study. This French study²⁰ of patients who had survived a heart attack had to be stopped early after just two and a half years because the trial diet was so effective compared to the control diet (a mildly modified Western diet). All-cause death was 70% lower in the trial group than in the control group.

While the Healthy Eating Pyramid suggests a moderate fat intake (of the right fats), a diet comparable to the Healthy Eating Pyramid except that it is low in fat seems to be just about as good. Dr Dean Ornish has published studies²¹ showing that a low-fat (10% fat) vegetarian diet resulted in a 60% reduction in adverse cardiac events in patients with moderate to severe coronary heart disease. Possibly the precise level of fat in the diet may not be critical, it may be the other features of the Healthy Eating Pyramid that confer most of the benefits. Some who are overweight may find it easier to lose weight on a low fat diet rather than on one higher in fat, but others may find that the palatability of a low-fat diet is less, making long term adherence to it difficult.

Because the Healthy Eating Pyramid is as soundly based as is currently possible on long-term research involving large numbers of humans (not animals!), it gives strong support for the healthiness of the vegan lifestyle and demonstrates the continuing convergence of scientific nutrition with veganism. That Professor Willett, although not himself vegan (he eats some chicken and fish), allows that a diet can be optimally healthy without including meat, dairy products or indeed any animal products at all, illustrates the recent shift in the thinking of the nutritional establishment away from animal products towards plant foods as the basis of a good diet. As well as supporting the vegan diet, the Healthy Eating Pyramid is an excellent basis for a vegan food pyramid.

Optimal nutrition however does not automatically ensue from simply avoiding animal products. This would only meet one of Professor Willett's recommendations (emphasise plant proteins). There are still the other six recommendations given above which vegans should seriously consider.

In conclusion, Eat, Drink and be Healthy is a diet book that it is virtually unique in being based on good long-term human evidence (as opposed to guesses, short-term experiments on humans or animal experiments) and, significantly for vegans, it shows that this evidence is entirely consistent with the optimal healthfulness of an appropriately chosen vegan diet.

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