The findings from a recent clinical trial shed light on the effectiveness of time-restricted eating as a method for weight loss. Time-restricted eating, a form of intermittent fasting, involves limiting the daily eating window within a specified timeframe while abstaining from caloric consumption outside of that window. The trial, conducted by senior researcher Krista Varady and her team at the University of Illinois Chicago, aimed to create a real-world scenario to examine the impact of this approach.
Ninety adults with obesity participated in the trial and were randomly assigned to one of three groups: time restriction, calorie-counting, or a control group. The time-restriction group followed a daily eating window from noon to 8 p.m. for the initial six months, and then they were allowed to expand it to 10 a.m. to 8 p.m. for the subsequent six months. On the other hand, the calorie-counting group aimed to reduce their daily calorie intake by 25% with the guidance of a dietitian. The control group made no changes and served as a comparison.
The results of the trial showed that both the time-restriction and calorie-counting groups experienced significant weight loss, while the control group gained weight over the course of one year. On average, participants in the diet groups lost around 8 to 9.5 pounds, which demonstrated comparable effectiveness between the two approaches. Importantly, the trial emphasized the importance of support in achieving weight loss goals. Participants in both diet groups received regular dietary counseling sessions, which likely played a significant role in their success.
Dr. Adam Gilden, who co-wrote an editorial alongside the study, noted that patients frequently inquire about time-restricted eating but cautioned against oversimplifying its implementation. While time restriction offers a straightforward approach to weight loss by focusing on eating within a specific timeframe rather than counting calories, it still requires effort and commitment. Gilden highlighted the significance of having support throughout the weight loss journey, such as consulting with a healthcare professional or seeking assistance from programs like Weight Watchers.
One concern associated with time-restricted eating is that it primarily concentrates on limiting food intake rather than promoting healthier food choices. The study found that participants’ diet quality did not significantly improve, but it also did not worsen. Improving diet quality is recognized as a challenging aspect of weight loss due to entrenched food preferences and factors such as income and access to healthy food. While time-restricted eating can be a starting point, Gilden stressed the importance of gradually transitioning toward healthier eating habits to maximize overall health benefits.
While time-restricted eating can be pursued independently, the study suggests that individuals may find greater success by seeking support from healthcare professionals or joining groups that offer guidance and accountability. Varady acknowledged that some individuals may experience initial side effects, such as headaches, nausea, or dizziness, as their bodies adjust to the new eating schedule. It is also important to note that time-restricted eating is not suitable for everyone, including pregnant women, individuals with a history of eating disorders, and those taking medications that require timed food intake.
In summary, the clinical trial provides valuable insights into the effectiveness of time-restricted eating as a weight loss strategy. While it offers a simplified approach compared to calorie counting, the support of healthcare professionals and the gradual incorporation of healthier food choices are vital for long-term success. Time-restricted eating can serve as a foundation for weight loss efforts, but it should be approached with awareness and consideration of individual circumstances and needs.