It’s become a well-known, yet somewhat controversial, method of improving weight loss results- intermittent fasting. Many people support that the body benefits from a period without food after it has finished burning calories since the last meal. Not only do some advocates say it helps weight loss, but some say the method is a way to decrease inflammation, prevent heart attacks, and even improve joint health. But over time, studies have found that when it comes to weight loss, it does not result in greater results compared to non-restricted meal timing, and some of the weight loss can actually be lean mass- not fat.
A new study backs findings that intermittent fasting doesn’t result in long-term weight loss and the data also highlighted what may impact weight loss more than intermittent fasting is the size of meals throughout the day.
Participants of the study, published in The Journal of the American Heart Association, were told to eat only between 12:00pm and 8:00pm and abstain from eating at all other times. They were not given any specific instructions regarding caloric or macronutrient intake “so as to offer a simple, real-world recommendation to free-living individuals,” according to the authors.
“Cross-sectional studies have shown that a greater meal frequency was either not associated, or associated with a reduced prevalence of abdominal and general obesity, while two large-scale prospective cohort studies showed that greater meal frequency was associated with increased weight gain and BMI,” said Wendy L. Bennett, MD, MPH, an associate professor of medicine at Johns Hopkins University School of Medicine
In a prospective study, Bennett and colleagues recruited 547 participants from three health systems. The participants downloaded and used a mobile app to record the timing of meals and sleep for at least 1 day for 6 months. Researchers assessed weight and comorbidities data at each outpatient visit for up to 10 years before until 10 months after baseline and modeled weight trajectories.
The results were that the total daily number of large and medium meals was associated with increased weight during follow-up time, whereas the total number of small meals was associated with decreasing weight. But the researchers stated, “Duration from first to last meal, as well as other meal patterns, did not show a clear association with weight trajectory,” and “Our findings did not support the use of time-restricted eating as a strategy for long-term weight loss.”
What is likely behind the lack of significant weight loss with intermittent fasting isn’t the approach, as much as it is likely that despite the shorter window of time to consume food, people exceed the quantity of calories needed to maintain or lose weight. Add to it that many people may also follow the concept of grazing.
Grazing can be a great way to avoid sudden bouts of hunger and supports consistent blood sugar levels. But if portions and types of food aren’t watched, people can sail past a calorie deficit and end up eating well beyond their recommended daily caloric intake, resulting in weight gain. What this highlights though, is that either of these approaches themselves aren’t the culprits as much as it depends on how mindful the individual is on what they consume, and how much, when they do eat.
Shifting lifestyle habits in an effort to reach a healthy weight is no doubt a beneficial thing. Sticking to any approach is often the largest challenge (read here how to stay the course!), as is ensuring that the quality of foods is high, and the quantity of foods supports your energy needs.