When I was little, I ate meats only on very rare occasions, for example, during holidays and wedding ceremonies. During that time, meats were precious foods. My dream then (and probably most Chinese people’s dream) was able to eat meats everyday.

Craving meats is hardwired in our genes. The taste of fat and the joy of chewing meats are so addictive that I can’t live for more than three days without eating meats. It is truly blessing that I am living in a society in which meats are cheap and abundant.

But wait, it seems that the body is not ready for the abundance of meats. Extra energy and fat stored in adipose tissues, originally prepared for the food crisis which never comes in industrialized societies, now become a burden to the body. In a sense, the body doesn’t know how to appropriately handle the overloaded fat.

There are foods other than meats that the body can’t handle appropriately. Even extra carbohydrates and proteins can be harmful. High-carbohydrate diet can cause insulin resistance by raising insulin level too fast and too much. High-protein diet may damage your kidney by overworking it. High-fat diet, needless to say, causes all troubles you have heard: diabetes, heart diseases, cancer, et al et al.

What kind of food combination is the best diet for our health? This is a paramount question. To answer it, we need to be specific, and a measurable outcome is desirable.

Hypertension, high blood pressure, is a reasonable start. It affects one of every four Americans. It is a dangerous risk factor of heart disease and stroke but unfortunately hard to detect in the earlier stage.

The blood pressure is the pressure of blood on the arterial walls. The systolic blood pressure is the pressure when blood pumped out of the heart, and the diastolic blood pressure is the pressure during the intervals when heart stops pumping blood. An elevated blood pressure (SBP/DBP above: 140mmHg/90 mmHg) may be caused by an increase of cardiac output, lack of elasticity of arterial vessels, and/or an increase of total resistance of peripheral blood vessels.

Hypertension needs to be treated, and the first treatment is diet. There are several milestone trials addressing the dietary factors.

The Trials of Hypertension Prevention (TOHP I and TOHP II), conducted during 1980s and earlier 1990s, established that weight loss and reducing sodium intake could lower blood pressure among people with high or high-normal blood pressure. Although it was not a strict feeding study in which participants were given foods to eat, the TOHP laid down the foundation for later research.

The Dietary Approach to Stop Hypertension (DASH) study investigated the role of fat in lowering the blood pressure. The original DASH diet was rich in vegetables and fruits, lower in saturated fat, and contained a lot of whole grains and fiber. Compared with the usual diet and the high vegetables and fruits diet, the DASH diet incurred a larger reduction in the blood pressure. Furthermore, the DASH-sodium diet in which sodium intake was reduced from 3,000mg to 1,500 mg per day, the reduction in blood pressure was even more striking. Therefore, the National Heart, Lung, and Blood Institute has recommended the DASH-sodium diet to control the blood pressure.

The recent Omini heart trial further examined the effects of protein, monounsaturated Fat, and carbohydrate on BP and Lipids. There were three types of diets in this study. The high-carbohydrate diet was a modified DASH diet in which the carbohydrate contents were increased. In the high-protein diet, they also started with the DASH diet and substituted the animal proteins with vegetable proteins, and reduced the carbohydrate contents by choosing low carbohydrate foods such as higher fiber vegetables. In the low fat diet, they used vegetable oils to supply monounsaturated fat. All three diets had low saturated fat contents and were rich in vegetables and fruits.

Compared with the high-carbohydrate diet, the high-protein diet achieved the largest reduction of blood pressure and the best improvement in lipid profile, followed by the low fat diet. The evidence is so convincing that the new diet will go into the next dietary guideline for certain.

Then, what’s the implication of an optimal diet? What do you mean a diet rich in vegetables and fruits, lower in saturated fat, and higher in vegetable proteins? Here are some hints for your daily grocery shopping.

First, buy a variety of vegetables and fruits. Try to avoid high carbohydrate vegetables such as potatoes and other starch foods. Leafy vegetables such as cabbage are good source of fiber and potassium.

Second, buy enough vegetable proteins such as beans, nuts, and legumes. Tofu is a good substitute for animal proteins.

Third, use vegetable oils with high monounsaturated fat. But be warned, try to avoid processed vegetable oils such as margarine which is high in trans-fat, the new bad fat.

Fourth, buy white meats such as chicken instead of red meats such as beef and pork. If possible, eat fish at least once every week. It has good source of other nutrients such as DHA.

Fifth, reduce the amount of food you eat every meal in addition to reducing the meat intake. For most people, 2000 calories per day is enough.

Sixth, my favorite recommendation, is to have a soup with very low sodium every dinner. It may seem tasteless at first, but it gives you plenty of fluid and also reduces the sodium intake overall. I am constantly persuading my wife to stick to this recommendation, and although only partially successful, now we often find meals from other families are too salty.

Finally, drink milk and eat eggs (including yolk if your cholesterol is not high). They are the best optimized natural foods available. Practically, you may not need any meat if you drink milk and eat eggs every day.

Anyway, diet suggestions from clinical trials are hard to follow because there are too many subtleties in their menus. Sometimes they are impractical. An optimal diet is nothing mysterious. It is the diet that our prehistoric human beings generated. It is the diet that fits our slow adapting bodies. Healthy foods are not energy rich foods.