Dr. Shahar Madjar

I have written here on several occasions about intermittent fasting for weight loss. But it seems that there is always more to say about diets in general and intermittent fasting in particular. In a study published in the prestigious New England Journal of Medicine, a new question was examined: is intermittent fasting in combination with caloric restriction better than caloric restriction alone.

Here are a few words about each of these diets:

Caloric restriction has been the recommended diet for the treatment of obesity. The idea is simple: consume fewer calories than you spend and weight loss will follow. Unfortunately, implementing the idea isn’t as simple. It requires focus and determination. It calls for some degree of obsessiveness. Calories need to be counted, portions to be controlled. Caloric restriction diets are therefore difficult to sustain over time.

Time restriction of food consumption (also known as intermittent fasting) seems easier. No more calorie accounting, or portion control. Instead, limit the number of hours in which food is consumed. A popular regimen is the 7-11 regimen in which dieters are encouraged to fast between 7 PM and 11 AM on the following day. Like in the case of caloric restriction, the idea here is also clear: restricting the number of hours in which food is consumed would invariably lead to a reduction in caloric intake, and, potentially (this hasn’t been proved beyond reasonable doubt) will jump-start the body into a new phase of higher metabolic activity and faster weight loss.

Nearly all the studies on intermittent fasting resulted in weight loss (2.5-9.9% of body weight) and also in a decrease in fat mass. However, studies comparing intermittent fasting to caloric restriction didn’t fully support the superiority of one diet over another. One such study (79 participants) showed that both groups lost a similar amount of weight (6.8% of body weight at 6 months) and that their fat mass and fat distribution were similar.

Which brings me to this new study I alluded to at the opening of this article. The study was conducted in Guangzhou, China in collaboration with researchers from Tulane University in New Orleans. It examined the question of whether caloric restriction in combination with time restriction (intermittent fasting) is superior to caloric restriction alone.

The researchers randomly divided the 139 participants into two groups. Both groups received dietary counseling including instruction booklets and sample menus. Both groups were instructed to write a daily dietary log and to take photographs of the food they consumed. All the participants met with a health coach every two weeks and attended health education sessions monthly. Participants in both groups were instructed to limit their caloric intake (1500-1800 calories a day for men and 1200-1500 calories a day for women).

Shahar Madjar, MD, MBA, is a urologist and an author. He practices in Michigan, at Schoolcraft Memorial Hospital in Manistique, and in Baraga County Memorial Hospital in L’Anse. Find his books on Amazon. Contact him at smadjar@yahoo.com