Parade.com talked with doctors to find out—here’s what we learned.
What is intermittent fasting?
First, let’s look at intermittent fasting in a little more detail. Intermittent fasting is an approach that focuses more on when you eat, not what you eat. You limit your calorie consumption to specific periods of time. But there’s not just one type of pattern. In fact, there are numerous ways to fast intermittently. The most commonly used approaches include:
5/2. With this version, you eat normally five days out of every week, but you strictly limit your calories on the other two days, which are not consecutive. Typically, you’d allow yourself about 500 or 600 calories total on the fasting days.
16/8. You fast for 16 hours, and you eat during the remaining eight hours. Some people alter this approach and fast for 18 hours, leaving themselves a six-hour window in which to eat.
Some people prefer other versions, like the alternate day approach, when you eat one day and fast the next. And some people like to fast for even longer periods of time, like 36 or 48 hours. Experts suggest that intermittent fasting has multiple benefits, too. “IF can be a beneficial way of promoting body fat loss and improving health,” says Erin Palinski-Wade, RD, CDE, a nutrition consultant and author of several books, including Belly Fat Diet for Dummies. “Research on IF has shown it can promote weight loss, help to reduce dangerous visceral fat levels and improve insulin resistance.”
Does your body type play a role in success?
In the 1940s, psychologist W.H. Sheldon described three main body types, or somatotypes:
Ectomorph, a slim and lanky body typeEndomorph, a rounder shape, often with a wide waistMesomorph, a more muscular type
You may recognize yourself in one of these three extremes, or you may fall somewhere in between. So, could your specific body type affect your success with intermittent fasting? Maybe—but the truth is, it hasn’t been studied enough for doctors to give any definitive answers. According to Colleen Tewksbury, PhD, MPH, RD, president of the Pennsylvania Academy of Nutrition and Dietetics, there’s not a lot of scientific evidence suggesting that there’s a weight loss strategy that’s best suited for each body type. “It is possible,” says Tewksbury, who’s also a spokesperson for the Academy of Nutrition and Dietetics. “We may find that to be the case, five to 10 years from now.” Doctors currently aren’t very concerned with specific body type, but more so the waist circumference of their patients. A larger waist circumference is a risk factor for certain chronic health conditions that are associated with carrying around more weight, like metabolic syndrome or diabetes. So, you could think of body type more in terms of how it’s linked to body composition, notes Sarah Thomson Ferreira, MS, MPHD, RN, a dietitian with the Cleveland Clinic’s Center for Functional Medicine. For example, if your body type is endomorph, you may be more likely to carry extra fat around your midsection and have a larger waist circumference. You may be more likely to be insulin resistant, too, which can make weight loss more challenging, notes Palinski-Wade. And losing weight, even a modest amount like 3-7% of our body weight, can improve the health factors associated with a larger waist circumference, says Tewksbury. So if any version of intermittent fasting can help you achieve that, great. Studies suggest the specific approach toward weight loss doesn’t seem to matter, although that could change with future research, Tewksbury notes. Sunitha Posina, MD, an internist in New York City, notes that people with a mesomorph body type and a medium build may be able to lose a few pounds with IF—but that’s not the only way. “However, it can be done by other balanced nutrition plans also," she says.
Is intermittent fasting right for you?
No matter what your body type, if you’re looking to lose weight the most important thing it to find a healthy, safe eating plan—whatever the means for you. “One thing people must realize is that it’s not for everyone and that similar benefits can be achieved with consistent and other well-balanced nutrition and lifestyle regimens,” says Posina. Many people who choose IF like the simplicity of it, as there’s very little or even no calorie counting or tracking involved. “This simplicity can improve compliance for some, which can improve overall weight loss success and maintenance,” says Palinkski-Wade. If weight loss is your goal, the most important thing is to find an approach that’s sustainable. “It’s less about what is the best approach and it’s more about what is the best approach for you,” says Tewksbury. Next up, here’s what one woman’s experience with intermittent fasting was actually like.
