Eating A Big Breakfast And Light Dinner Doesn't Cause As Much Weight Loss As You Think

In today's diet trends of intermittent fasting and meal timing, we hear that the time of day we eat can affect how our food is metabolized. We're told that it's better to "eat breakfast like a king, lunch like a prince, and dinner like a pauper," with the goal of using these calories more during our waking hours. According to a recent study in Cell Metabolism, the time we choose to eat our biggest meal has little effect on overall weight loss.

The study recruited 30 healthy participants who had a body mass index above 27. Each person participated in two four-week diets with a reset week in between. The morning-loaded diet consisted of 45% of the daily calories at breakfast, 35% at lunch, and 20% at dinner. The evening-loaded diet had 20% of total calories in the morning, with 35% at lunch, and 45% at dinner. Both diets consisted of relatively the same amount of daily calories and consistent protein, carbohydrate, and fat ratios. The researchers provided participants with all the food and drinks to stick to a consistent number of calories. They also measured how much energy the participants expended during the day.

At the end of each four-week diet, the participants lost the same amount of weight and saw no difference in how much energy they spent throughout the day. "Calorie utilization does not vary with time of day, suggesting that metabolic adaptation does not provide the basis for the enhanced weight loss associated with morning calorie loading seen in other studies," the researchers concluded.

This doesn't mean that the "breakfast like a king" model is strictly a myth. When the participants ate most of their calories in the morning, they felt less hungry throughout the day and had a smaller appetite. The researchers suggested that dieters who ate bigger breakfasts were more likely to stick to their diets because they weren't as hungry the rest of the day.

The study acknowledged that the four-week diet plans were much shorter than other studies that found weight loss differences between morning and evening eaters. A 2013 study in Obesity found that those who ate a 700-calorie breakfast, 500-calorie lunch, and a 200-calorie dinner for 12 weeks had greater weight loss than the group who ate the smaller breakfast and larger dinner. A 2013 study in the International Journal of Obesity grouped people according to early or late eaters. Researchers found that those who ate most of their calories before 3 p.m. lost more weight over 20 weeks. This recent study had each participant partake in both eating methods.