One of the most pervasive myths regarding meal timing is that you should eat six small meals every few hours to increase metabolism and lose weight. In fact, research shows that this approach often backfires and may lead to weight gain and worse metabolic function.
The theory behind the six meals-a-day recommendation is that when you eat, you raise your metabolic rate slightly by increasing the thermic effect of food—that is, the calories burned as the body processes a meal. However, the additional number of calories burned is minimal, and studies show that frequent meals have other metabolic and behavioral drawbacks that make it a bad choice for weight management.
First, although it would make sense that frequent meals would help reduce hunger and theoretically lower calorie intake, research shows this is not the case. Studies show no significant difference between eating 3 or 6 meals in terms of hunger ratings and there is some evidence that a higher meal frequency may actually increase hunger, especially in obese people. High frequency eating or grazing impairs circadian rhythm (your internal body clock), leading to altered levels of hormones involved in hunger and satisfaction.
Another problem with a higher meal frequency is that people are surprisingly bad at portion control and tend to significantly underestimate the amount of calories they are eating in a meal. Surveys show that even when people are actively counting calories, they underreport what they eat by an average of 47 percent. This means that for every eating opportunity, you have a chance of overshooting calorie needs and underestimating how much you ate. By reducing your “eating opportunities,” you have fewer chances to overeat calories, which will pay off in terms of weight management or fat loss.
There are also surprising benefits to limiting your meal frequency to three or fewer a day. Fewer meals gives your GI tract a chance to rest, which is important for something called “gut motility.” Gut motility occurs once digestion is finished and muscles of the GI tract stretch and contract, enabling food to progress through the intestines, while at the same time, ensuring absorption of nutrients.
Fewer meals can also be better for metabolic health. When you eat frequent meals, blood sugar and insulin stay elevated, never allowing the body to shift into fat burning mode. You also experience a reduction in fat burning enzymes, impairing metabolic flexibility or the ability to use both glucose and fat for energy. This may have the side effect of stimulating hunger any time glucose levels drop, leading to a higher total calorie intake.
A high meal frequency can be harmful to metabolic organs such as the liver and pancreas. Both play critical roles in your body’s ability to burn fat and glucose, and frequent meals can impair their function and lead to fat deposition in the liver.
Determining the number and timing of meals will be individualized based on age, body composition, metabolic health, goals, physical activity, etc., but here are some general recommendations:
Eat two to four times a day, allowing at least four hours between meals. Choosing a lower meal frequency and eating about every four hours can allow you to prevent excessive hunger, while giving the body a chance to burn fat and avoid the negative metabolic effects of chronic eating.
Use an 8- to 12-hour eating window. Recent studies show that the average person is eating their entire waking day with most people noshing over the course of 15 hours. Not only does this constant eating disrupt circadian function, it leads to greater calorie intake, predisposing you to fat gain. By shortening your eating window to 12 hours or less, you give the GI tract a rest and allow for fat burning and improved metabolic function.
Eat during daylight. How often do you load up on coffee and skimp on healthy meals during the day only to gorge on calories in the evening? Eating the majority of your calories at night is associated with obesity and metabolic disorders like diabetes that hamper circadian function and hormone release.
Think about our ancestors—they hunted, gathered, and feasted during daylight, fasting from dusk til dawn. Adopting a similar pattern is healthful and can even aid with weight loss: One study found that when overweight volunteers consumed the majority of their calories earlier in the day (700 calories at breakfast, 500 at lunch, and only 200 at dinner) they lost more body fat than a group that had the opposite eating pattern (100 calories at breakfast, 500 at lunch, and 700 at dinner).
Final Words: Personalizing your meal timing is an important tool that can allow you to minimize hunger, while maximizing nutrition for better metabolic health and optimal body composition.
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