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This Popular Eating Habit May Not Help You Lose Weight, Study Says

A doctor advises keeping close track of the effects intermittent fasting has on your body.
intermittant fasting

Time-restricted eating, also known as intermittent fasting, has been in the research spotlight lately, specifically with questions about whether this way of eating is a boon to weight loss or a bust instead.

What's the latest research around intermittent fasting?

A recent study presented at the American Heart Association's Scientific Sessions takes the latter view. In this particular research, 41 overweight adults with either prediabetes or diabetes were followed in a 12-week study, with half of them sticking to a time-restricted eating pattern of eating 80% of their day's calories before 1 pm. The other participants consumed half their daily calories after 5 pm daily, which to clarify, is a fairly standard eating pattern among Americans. (Related: 21 Best Healthy Cooking Hacks of All Time.)

Although people in both groups lost some weight, researchers were surprised that the early-eating group didn't show more notable results.

"We thought that the time-restricted group would lose more weight," study author Nisa Maruthur, M.D., associate professor of medicine, epidemiology, and nursing at Johns Hopkins University, said in a statement. "Yet that didn't happen. We did not see any difference in weight loss for those who ate most their calories earlier versus later in the day."

However, this isn't the first time intermittent fasting has shown mixed results. Some studies have noted potential health advantages, such as reduced inflammation, better gut function, more efficient cognitive processes, and lower cholesterol. But another recent study out of the University of California, San Francisco found that intermittent fasting may result in a significant amount of muscle loss.

So, does intermittent fasting work for weight loss or not?

The answer to that question is likely more individualized than studies might suggest, according to Jason Fung, M.D., author of "The Complete Guide to Fasting" and "The Obesity Code."

"Like any kind of change to your eating habits, intermittent fasting benefits will depend on how you use it," he says. For example, if you're loading up on highly processed, very caloric foods but doing it within a shorter timeframe, it's unlikely that the smaller eating window will have any benefit.

"If you're eating junk and just doing it in a shorter amount of time, that's not going to do much for you except perhaps lead you to overeat," he adds. (Related: 3 Surprising Warning Signs You're Eating Too Much.)

However, if you're trying the method as a "reset" toward changing your eating habits in a healthy way, you're much more likely to see benefits, including potential weight loss, he clarifies. Also, keep in mind that although the term "intermittent fasting" is thrown around often, there isn't a one-timeframe-fits-all approach that's supposed to work for everyone, Fung says.

What are some of the different types of intermittent fasting?

"There are numerous ways to do time-restricted eating, so it often takes some effort to play around with what works best for you, if anything," he adds. Some people, for example, restrict eating to an 8-hour window, while others do 10 hours or 12 hours. Some prefer to fast completely for 24 hours, once a week.

"Tracking your efforts and your results is helpful," he suggests. "That means not only your weight, but also other potential effects like your energy level, mood, and sleep quality. Give yourself at least a few days to a week as a tryout for a new strategy."

It's also possible that intermittent fasting is not your groove, and that's okay too. Still, simply trying this way of eating is likely to make you more conscious of not just when you eat, but also of what you're consuming.

If anything, intermittent fasting can help you become more aware of hunger cues as well as the types of foods you're choosing to fuel your body.

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Elizabeth Millard
Elizabeth Millard is a freelance writer specializing in health, fitness, and nutrition. Read more