Trying to Lose Weight? Your Success Depends on This, New Study Says


Roughly half of Americans report having intentionally tried to lose weight in the last 12 months. And while it would be easy to chalk this up to our diet-obsessed culture, for some people it also reflects a deeper desire for better health. After all, over 40 percent of Americans are considered obese, and another 30 percent are overweight; both groups are at increased risk of disease and life-threatening illness, including heart attack, stroke, dementia, and more.

Though even modest weight loss can significantly lower your odds of these conditions, Harvard experts are now sharing a word of caution for those hoping for a full body transformation: your success in losing weight and keeping it off may be dependent on one factor in particular. To complicate matters further, a particular demographic may be at higher risk of diabetes after attempting to lose weight. Read on to learn what your weight loss success may depend on, and why experts say intentional weight loss may not be the answer for everyone.

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Maintaining a healthy weight can boost your health.

When achieved safely, weight loss makes a major impact on your health. "Even a modest weight loss of five percent to 10 percent of your total body weight is likely to produce health benefits, such as improvements in blood pressure, blood cholesterol, and blood sugars," says the Centers for Disease Control and Prevention (CDC). "For example, if you weigh 200 pounds, a five percent weight loss is 10 pounds, bringing your weight down to 190 pounds. While this weight may still be in the 'overweight' or 'obesity' range, this modest weight loss can decrease your risk for chronic diseases related to obesity," CDC experts note.

However, new research has recently suggested that weight loss doesn't benefit everyone equally. Some people are likely to see greater long-term success—and more health benefits—than others, according to a new study published in the journal PLOS Medicine.

READ THIS NEXT: 7 Medications That Could Be Making You Gain Weight, Pharmacists Say.

Weight loss success depends on this, a new study says.

The new study, conducted by researchers at Harvard University's T.H. Chan School of Public Health, looked at the association between various weight loss strategies and long-term weight loss, as well as diabetes risk. The team found that successful, long-term weight loss is often dependent on a person's starting weight. Individuals categorized as obese, defined as having a body mass index (BMI) of 30 or above, were most consistently able to lose 4.5 kg—roughly 10 pounds—and keep it off.

The researchers reviewed a range of weight loss strategies, including eating a low calorie diet, exercising, doing a combination plan of diet and exercise, fasting, following a commercial weight loss program, and taking weight loss pills. Study participants with a BMI over 30 saw success using each of these strategies, except for use of weight loss pills.

People with a lower BMI may not benefit from intentional weight loss strategies.

Those with a "lean" body type—defined as having a BMI under 25 at the start of the study—saw very different results. Among that group, those who intentionally lost 4.5 kg regained more weight in the four years that followed, and had a higher risk of developing Type 2 diabetes than those with the same BMI categorization who did not attempt to lose weight at all. The mid-range group with a BMI between 25 and 30 also eventually regained the weight and experienced a heightened diabetes risk.

"We were a bit surprised when we first saw the positive associations of weight loss attempts with faster weight gain and higher Type 2 diabetes risk among lean individuals," said Qi Sunn, MD, SciD, a study author and associate professor in the Departments of Nutrition and Epidemiology at the T.H. Chan School of Public Health. "However, we now know that such observations are supported by biology that unfortunately entails adverse health outcomes when lean individuals try to lose weight intentionally. The good news is that individuals with obesity will clearly benefit from losing a few pounds and the health benefits last even when the weight loss is temporary," he added, while speaking with SciTechDaily.

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This strategy was the most successful overall.
iStock / FreshSplash

Though all of the weight loss strategies saw relatively modest results in the long-term, one strategy stood out for having the best outcome. Following an exercise plan alone, rather than a combined plan of exercise and dieting, was associated with the most weight loss over the course of four years. Individuals with a BMI over 30 saw a 4.2 percent weight reduction over that time when using exercise alone, a 2.7 percent reduction with exercise and diet, and a one percent reduction with diet alone. This represented a 21 percent health risk reduction for the group who exercised.

Though somewhat counterintuitive, given that diet and exercise combined would most likely lead to faster weight loss, this could reflect the old adage that the best weight loss plan is the one you can stick to.

Not sure whether weight loss would benefit your health? Speak with your healthcare provider for more information on whether a weight loss strategy is right for you.