Meal timing vs meal size: which is better for weight loss? A new study suggests an answer
While intermittent fasting continues to be one of the most popular weight loss methods, a new study published in the Journal of the American Heart Association has found that some people can achieve their weight loss goals without limiting their eating to certain times of the day. Over the course of a 6-year study, researchers at Johns Hopkins University found that calorie count per meal seemed to have a greater impact on weight loss than the timing of the meal did.
The Study: Tracking small, medium, and large meals
The study involved 547 participants of various weights, including those who were overweight or had severe obesity. For six months, participants logged their eating and sleeping habits in a mobile app. The app collected a range of data that included their sleep times, how long they slept, when they ate, and the size and calorie density of their meals. The participants also completed surveys about their physical activity level, whether or not they were actively trying to lose weight, smoking habits, and other lifestyle factors.
Categorizing meals by calorie content
Most notably, participants were asked to separate their meals into 3 size categories when they logged them: a small meal had fewer than 500 calories, medium meals fell between 500 to 1,000 calories, and large meals were more than 1,000 calories.
Pre- and post-study data collection
Researchers then used electronic health records to look at how much the participants weighed over the course of around six years—at least five years before they’d enrolled in the study, and roughly half a year after.
The Results: Meal size matters more than timing
The researchers found that the participants who logged the most medium and large meals gained weight over six years, while those who ate fewer, smaller meals lost weight. These findings support the widely-held belief that consuming fewer calories contributes to weight loss.
However, data did not suggest any link between weight change and restricting eating to certain times of the day. This included the timing of meals around sleep—a snack before bed or the timing of breakfast after waking was not linked to weight change.
Findings suggest that meal size, as opposed to meal time, has a greater impact on weight change.
In sum, the findings suggest that changing your eating times during the day, or extending your fasting window between dinner and the following day’s breakfast, is not necessarily going to prevent weight gain. Thus the study authors concluded that the most dependable weight loss strategy, especially for maintaining a lower weight long-term, continues to be eating fewer large meals and more small meals.
Click here to read the full study for details on the process and findings
The Takeaways
According to this study, meal size, as opposed to meal time, has a greater impact on weight change. However, while the findings are interesting, it is worth noting that this is a relatively small sample size, and the weight gains reported in the study were not significant—an average of 1-2 pounds a year. Furthermore, the data relied on the participants’ ability to accurately estimate the calories contained in each of their meals, which can often prove difficult.
Comparing the effectiveness of intermittent fasting
Another reason it is too soon to completely rule out intermittent fasting as a plausible weight-loss method is that other studies, including this one in 2015 and this one in 2021, have shown intermittent fasting can be effective. As well, there are other types of intermittent fasting outside of timing meals around sleep and breakfast that were not considered in the study (for example, not eating on one day a week, or skipping lunch as opposed to breakfast).
Individualized approaches for successful weight loss
In the end, it is best to take a more individualized approach. Success is not guaranteed for those that modify their diets to consist of smaller meals, and some patients see excellent results after adopting intermittent fasting.
If you are looking to lose weight, it is important to do what you feel suits your body and mind best. As long as you are consuming enough calories and nutrients to sustain your physical health, it is up to you to decide what you eat and when you do so. If this is difficult—and it is for millions of people—we encourage you to reach out to a qualified health professional who can support you in safely meeting your goals.
Our Inland Empire weight loss doctors are here for you
The highly experienced weight loss surgeons of Surgical Arts of Inland Empire are here to help you reach your goals and feel more comfortable in your body. We offer free consultations so you can become educated about a full range of treatment options, meet our team, and decide if we are a good fit for you. Call our Rancho Cucamonga office at (909) 579-3111 or contact us online to book a personal meeting to discuss your goals and learn more about your weight loss options.
