Diet & Weight Loss

A healthy weight is an important element of good health. How much you eat—and what you eat—play central roles in maintaining a healthy weight or losing weight. Exercise is the other key actor.

For years, low-fat diets were thought to be the best way to lose weight. A growing body of evidence shows that low-fat diets often don't work, in part because these diets often replace fat with easily digested carbohydrates.

Hundreds of diets have been created, many promising fast and permanent weight loss. Remember the cabbage soup diet? The grapefruit diet? How about the Hollywood 48 Hour Miracle diet, the caveman diet, the Subway diet, the apple cider vinegar diet, and a host of forgettable celebrity diets?

The truth is, almost any diet will work if it helps you take in fewer calories. Diets do this in two main ways:

  • getting you to eat certain "good" foods and/or avoid "bad" ones
  • changing how you behave and the ways you think or feel about food

The best diet for losing weight is one that is good for all parts of your body, from your brain to your toes, and not just for your waistline. It is also one you can live with for a long time. In other words, a diet that offers plenty of good tasting and healthy choices, banishes few foods, and doesn't require an extensive and expensive list of groceries or supplements.

One diet that fills the bill is a Mediterranean-type diet. Such a diet—and there are many variations—usually includes:

  • several servings of fruits and vegetables a day
  • whole-grain breads and cereals
  • healthy fats from nuts, seeds, and olive oil
  • lean protein from poultry, fish, and beans
  • limited amounts of red meat
  • moderate wine consumption with meals (no more than two glasses a day for men; no more than one a day for women

A Mediterranean-style diet is a flexible eating pattern. People who follow such diets tend to have lower rates of heart disease, diabetes, dementia, and other chronic conditions.

Diet & Weight Loss Articles

Cutting red meat-for a longer life

Red meat: in addition to raising the risk for colorectal cancer and other health problems, it can actually shorten your life. That's the clear message of the latest research based on data from two ongoing, decades-long Harvard School of Public Health studies of nurses and other health professionals. It appears "healthy meat consumption" has become an oxymoron. More »

Losing weight may require trial and error

No weight-loss approach works for every heart patient. If you have tried different diets and are diligent about exercise, but those extra pounds won't budge, you may not have found the right approach or combination of approaches for you. "Everything works for some people, but no treatment is equally effective for everyone," says Dr. Lee Kaplan, director of the Obesity, Metabolism and Nutrition Institute at Massachusetts General Hospital. "No method is fundamentally better than any other. The key is finding out which therapy is best for you, and that takes trial and error," he says. When you are trying to lose weight, Dr. Kaplan advises you to take it one step at a time. "Try what feels good, don't despair, and don't give up.” (Locked) More »

Major fat-burning discovery

  Harvard researchers have discovered a hormone released by exercise that turns energy-storing white fat cells into energy-burning brown fat cells.   More »

Certain dietary patterns are associated with long-term brain health

Scientists have long known that certain nutrients are essential for brain development and function. There's also evidence that good nutrition can help stave off cognitive decline in older people. But studies of single nutrients have largely been disappointing, and research on the relationship between overall diet and brain function generally relies on food frequency questionnaires, which can be misleading because of faulty memories and the inability to take account of nutrient absorption. Now researchers have conducted the first study using nutrient biomarkers and brain imaging to analyze the effect of diet on cognitive function and brain volume. Their main finding is that higher blood levels of omega-3 fatty acids and vitamins B, C, D, and E are associated with better memory and thinking in older people. (Locked) More »

Why stress causes people to overeat

There is much truth behind the phrase "stress eating." Stress, the hormones it unleashes, and the effects of high-fat, sugary "comfort foods" push people toward overeating. Researchers have linked weight gain to stress, and according to an American Psychological Association survey, about one-fourth of Americans rate their stress level as 8 or more on a 10-point scale. In the short term, stress can shut down appetite. A structure in the brain called the hypothalamus produces corticotropin-releasing hormone, which suppresses appetite. The brain also sends messages to the adrenal glands atop the kidneys to pump out the hormone epinephrine (also known as adrenaline). Epinephrine helps trigger the body's fight-or-flight response, a revved-up physiological state that temporarily puts eating on hold. But if stress persists, it's a different story. The adrenal glands release another hormone called cortisol, and cortisol increases appetite and may also ramp up motivation in general, including the motivation to eat. More »

Controlling what — and how much — we eat

We live in an environment that is brimming with food and drinks that satisfy our cravings for fat, salt and sugar — but these make us overweight, cause illness, and shorten our lives. An adult can get by on as little as 500 milligrams (mg) of sodium a day. But the average American intake is about seven times that amount, or 3,400 mg. Humans can certainly live without sugar (and, in fact, without any kind of carbohydrate as long as some fat and protein are available), but Americans now consume, on average, about 20 teaspoons of added sugar daily — and that's above and beyond the sugars found naturally in fruit, vegetables, and dairy products. There's nothing natural about today's food environment; agricultural and food policies and interests, past and present, determine food choices, prices, and even the locations where we can buy food. But as individuals, we must cope, choose wisely, and resist the temptations presented to us. Many people say that adopting diets low in salt, fat, sugar, or animal products alters their food preferences, and there's some scientific evidence to support this experience. Researchers have also investigated methods of modifying one's food preferences so more healthful foods will be more appealing. In general — and not unexpectedly — flavor and food preferences are more malleable when we're young (indeed, in utero), but as adults, we can still work on them. Some studies suggest that a baby's taste preferences can be altered by what the mother ate and drank while she was pregnant. In one often-cited study, researchers randomly assigned mothers to drink carrot juice or water during the last trimester of their pregnancy. The babies of mothers who drank carrot juice enjoyed carrot-flavored cereal more than the babies of the mothers who drank water (infant preferences can be deciphered from facial expressions). More »

November 2011 references and further reading

Cordero A, Bertomeu-Gonzalez V, Moreno-Arribas J, Agudo P, Lopez-Palop R, Masia MD, Miralles B, Mateo I, Quiles J, Bertomeu-Martinez V. Burden of systemic hypertension in patients admitted to cardiology hospitalization units. American Journal of Cardiology, published online Aug. 24, 2011. Salisbury AC, Amin AP, Reid KJ, Wang TY, Masoudi FA, Chan PS, Alexander KP, Bach RG, Spertus JA, Kosiborod M. Hospital-acquired anemia and in-hospital mortality in patients with acute myocardial infarction. American Heart Journal 2011; 162:300-309 e3. Salisbury AC, Kosiborod M, Amin AP, Reid KJ, Alexander KP, Spertus JA, Masoudi FA. Recovery From Hospital-Acquired Anemia After Acute Myocardial Infarction and Effect on Outcomes. American Journal of Cardiology 2011. (Locked) More »

What foods are included in the portfolio diet?

A study in The Journal of the American Medical Association found that a vegetarian diet emphasizing a “portfolio” of cholesterol-lowering foods did a better job of reducing low-density lipoprotein — the so-called “bad” cholesterol — than a low-saturated-fat vegetarian diet. All participants in the study followed a heart-healthy diet rich in fruits, vegetables, and whole grains (Locked) More »

Controlling what - and how much - we eat

Because humans have evolved to crave fat, salt, and sugar, it is difficult to shift away from them and toward a healthier diet, but it is possible to learn to like vegetables, fruits, and whole-grain foods more. Eating a variety of vegetables at a single meal is a way to encourage greater intake. If you keep an open mind and try a variety of vegetables, you might find varieties that contain bitter compounds to which you are less sensitive. The genetic variations that affect reactions to bitter-tasting vegetables may also influence a person's liking of whole grains.  One strategy for making whole grains more appealing is simply to mix in some refined grains. You can sneak more whole grains into your diet by substituting half the flour in cookie, muffin, or bread recipes with whole-wheat flour, mixing wheat germ into meatballs, meatloaf, or burgers or adding barley, a whole grain that's mild in flavor, as a thickener in soups and stews. (Locked) More »

Harvard researchers continue to support their healthy eating plate

Harvard Health Publishing, in conjunction with nutrition experts at Harvard School of Public Health (HSPH) first unveiled the Healthy Eating Plate in 2011. It's an evidence-based visual guide that provides a blueprint for eating a healthy meal. Like the U.S. government's MyPlate, the Healthy Eating Plate is simple and easy to understand—and it addresses important deficiencies in the MyPlate icon. "Unfortunately, like the earlier U.S. Department of Agriculture Pyramids, MyPlate mixes science with the influence of powerful agricultural interests, which is not the recipe for healthy eating," said Walter Willett, Professor of Epidemiology and Nutrition and chair of the Department of Nutrition at HSPH. "The Healthy Eating Plate is based on the best available scientific evidence and provides consumers with the information they need to make choices that can profoundly affect our health and well-being." View the Healthy Eating Plate. More »