There is a diet called ” intermittent fasting “. This is done by setting a period of food restriction called “fasting” (generally about 16 hours) that restricts the time you eat during the day, and eating normally only at other times. The idea is that it can help you lose weight, reduce your risk of disease, and extend your life.
It’s a popular way to lose weight, but a new study published on Jan. 18 in the Journal of the American Heart Association suggests that meal times themselves don’t help you lose weight.
The study was conducted on 547 adults by researchers at the Johns Hopkins University School of Medicine. Participants used a mobile app developed for this study to record their eating, sleeping, and waking patterns over six months. This detailed data gave researchers insight into how long it took them to wake up to eat, how long it took them to eat their first and last meal of the day, and how long it took them to sleep after their last meal. They found no relationship between meal times and changes in body weight.
“Our findings do not support the use of time-restricted diets as a strategy for long-term weight loss in the general medical population,” they conclude.
Speaking to CNN, study director Wendy Bennett said there was no signal in the data that compressing daily meals into smaller windows was associated with weight loss.
“Based on other research, including ours, we’re starting to think that the timing of meals in the day is unlikely to lead to immediate weight loss,” Bennett said.
“Experimental studies suggest that time-restricted diets may improve circadian rhythms and play a role in metabolic regulation, but our study detected an association in a wide range of weight populations. Importantly, more frequent and larger meals per day were associated with weight gain, suggesting that overall total caloric intake is the major driver of weight gain. ,” the study said.
Christa Varady, a nutrition researcher who studies fasting at the University of Illinois at Chicago, who wasn’t involved in the study, said, “The small sample size and whether participants chose large or small meal sizes did not affect the results. Several factors may cloud the results, including reliance on expression and not recording specific calorie counts, and the use of separate scales to weigh participants in the doctor’s office. There is,” he told Time.
However, Varady questioned the effectiveness of eating only at certain times. Varady said it’s not effective in and of itself, but if you limit the time you eat and you end up eating less, it can help you lose weight.
All of this, of course, does not mean that intermittent fasting strategies cannot help someone lose weight. However, it is becoming increasingly clear that the occasional weight-loss effects of these dietary strategies may be primarily mediated by reduced caloric intake. Fasting is certainly a great way to control your calorie intake, but eating as much as you want for as little as six to eight hours each day may not necessarily result in weight loss.
We aimed to assess the relationship between meal intervals and weight transition in a clinical cohort of adults.
Method and result
This study is a multicenter, prospective cohort study of adults recruited from three healthcare systems. During the six-month study period, 547 participants downloaded a mobile application and used it to record their meal and sleep timings for at least one day. Information on body weight and comorbidities were obtained at each outpatient visit from electronic medical records up to 10 years before 10 months after baseline. Mixed linear regression was used to model weight trends. The average age was 51.1 years (SD 15.0), the degree of obesity was 30.8 (SD 7.8) kg/m2, 77.9% were female, and 77.5% were Caucasian. The mean interval from the first meal to the last meal was 11.5 (2.3) hours and was not associated with weight change. The number of meals per day was positively correlated with body weight change. The mean difference (95% CI) in annual weight change for one additional meal per day was 0.28 kg (0.02-0.53).
The number of meals eaten per day was positively correlated with body weight change over the 6 years. Our findings do not support the use of time-restricted diets as a strategy for long-term weight loss in general practitioners.