Diet & Weight Loss Archive

As a person loses weight, the body reacts by lowering its metabolic rate to conserve energy, an evolutionary adaptation that makes it harder to lose additional weight. A study of participants from The Biggest Loser found that this metabolic adjustment persists for years.

News briefs

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Past studies have suggested that drinking coffee is associated with many health benefits, such as added longevity, lower blood pressure, less weight gain with aging, and a reduced risk of many diseases, including type 2 diabetes, liver disease, cardiovascular disease, several degenerative neurological diseases (like Parkinson's disease), and cancer. Now a massive review of more than 200 large studies, published Nov. 22, 2017, in The BMJ, backs up many of those links. The largest health benefits were associated with drinking three to four cups of coffee per day: drinking more than four cups per day did not bring additional benefits. It's not all good news, however; the study found that women who drank coffee had greater risks for fracture and pregnancy complications. But over all, the researchers say, coffee drinking appears to be safe. They caution that the findings are all based on observational studies, not randomized controlled trials — the gold standard of research.

Drinking a few cups a day seems to be safe for most people. But evidence that coffee protects your heart is pretty weak.

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Java junkies may have perked up after hearing that drinking coffee may lower heart disease risk. But are there grounds to support this claim?

In recent years, researchers have observed that people who drink about three cups of coffee daily may be slightly less likely to develop heart disease or to die from it than people who avoid the aromatic brew. A review article in the Nov. 22, 2017, issue of The BMJ that included nearly 300 studies on the health effects of coffee came to a similar conclusion. However, as the authors point out, their findings can't prove cause and effect. In the absence of long-term, randomized trials that assign people to drink coffee or not, it's impossible to say whether the popular drink (or some other factor) led to the lower heart risk.

If you want to keep your New Year’s resolutions, you need to approach them as a process of behavior change, make your goals realistic, and have a specific plan for how you will reach them.

Ask the doctor

Q. I'm very overweight, and my doctor has been urging me to consider bariatric surgery. I'm worried that, like the diets I've tried, it will work for a while and then stop working. Am I being too cautious?

A. Bariatric surgery involves any of several different surgical procedures on the stomach and intestine designed to reduce the calories your body absorbs from the food you eat. It also helps quell appetite. That's because, in all of us, when our stomach becomes empty following a meal, it starts to make a hormone (called ghrelin) that travels to the brain and stimulates appetite. Bariatric surgery seems to diminish the amount of that hormone.

It's called "weight bias," and even health care providers aren't immune.

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If you've ever delayed a doctor's appointment so you could lose a few pounds before your annual weigh-in, or hesitated to exercise in public because you felt self-conscious among a sea of hard-bodied gym goers, your weight may be affecting your health — but not in the way you might think.

Even if you're otherwise healthy, sometimes excess pounds bring increased health risks, especially if they keep you from following recommended health practices that offer protection over the long term.

Research we're watching

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Noshing on a handful of nuts on most days of the week has been linked to a lower risk of obesity and heart disease. New research may help explain why: walnuts appear to activate a brain region involved in appetite and impulse control.

For the study, nine people with obesity drank a smoothie that contained about 14 ground walnut halves or a placebo smoothie (identical in taste and calories) for five consecutive days. After a month on their regular diets, the participants returned for another five days, during which the placebo group drank walnut smoothies and vice versa. On day five of both periods, they underwent brain imaging tests while looking at pictures of desirable foods (such as burgers and cake), less desirable foods (vegetables), or neutral pictures of rocks and trees.

You've tried different diets — and have even been exercising regularly — but those extra pounds won't budge. Don't give up. It may be that you haven't yet found the weight-loss strategies that work 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."

You may be storing unhealthy amounts of visceral fat even if your weight appears normal.

For decades, the body mass index (BMI) has been the gold standard for gauging obesity-related heart disease risk. But this handy tool doesn't always tell the whole story. It extrapolates your body fat percentage based on your height and weight (see www.health.harvard.edu/bmi-calculator). But the formula can't assess how or where your body stores its excess fat — a distinction that is crucial for cardiovascular health. By some estimates, the BMI misclassifies nearly 50% of people who are at higher disease risk from excess fat, meaning that you can be overfat even when you're not overweight.

The secret life of belly fat

Some people are genetically programmed to have a lot of fat tissue under the skin, which is deployed to store extra food energy during times of scarcity. But other people have very few of these designated fat cells, explains Dr. Christos Mantzoros, professor of medicine at Harvard-affiliated Beth Israel Deaconess Medical Center.

Research we're watching

People who carry excess weight but have normal blood pressure, blood sugar, and cholesterol values are sometimes dubbed "fat but fit." But they're still more likely to develop heart disease than people who aren't overweight, a new study suggests.

Researchers analyzed more than 7,600 cases of heart disease that occurred over a 12-year period in 10 European countries. They also used data from 10,000 healthy people without heart disease as a comparison group. Compared with people at a healthy weight, those who were overweight or obese had up to a 28% higher risk of developing heart disease.