As every nutritionist will tell you, what you eat matters! A milkshake and an order of fast-food fries have a different impact on your body than a meal of salmon and broccoli. But more and more experts on nutrition now acknowledge that when you eat is important, too. In fact, preliminary research shows that meal timing is a factor in weight and blood sugar control. For example, eating larger meals earlier in the day and avoiding food intake late in the evening seems to better regulate blood sugar and reduce the risk of weight gain. You might think that meal timing exerts benefits mainly by its effect on metabolism or insulin sensitivity. However, a new study shows that when you eat can also impact your appetite and how much you eat.
What New Research Shows about Meal Timing and Appetite
Researchers asked a group of overweight adult males and females between the ages of 20 and 45 to take part in a study. The participants were asked to eat on different meal schedules. Each participant ate on each schedule at different times over the course of the study. For one schedule, the subjects ate three meals daily but dined during a 6-hour window period. For example, they ate breakfast at 8:00 a.m. and their final meal at 2:00 p.m. For the other schedule, the participants ate their meals over a 12-hour period. In this case, breakfast was at 8:00 a.m. and dinner at 8:00 p.m. The composition of their diets was similar.
The difference between the two was the amount of time the subjects fasted. For the first schedule, since they ate during a 6-hour window, they fasted for 18 hours daily. On the second schedule, they fasted only 12 hours daily. To look at the impact of each schedule on metabolism, researchers asked the participants to spend time in a respiratory chamber so they could measure how many total calories they burned as well as the total calorie burn by macronutrient–carbs, protein, and fat. They also measured levels of key appetite hormones and documented how hungry the participants felt.
The results? The participants who ate their meals during the 6-hour feeding window had lower levels of ghrelin, a hormone that boosts the desire to eat. They also felt less hungry than they did on the 12-hour feeding schedule. In addition, the subjects burned more fat over a 24- hour period when they ate on the 6-hour schedule, although it didn’t affect the total number of calories they burned.
What does this mean? It suggests that consuming meals within a shorter time frame during the day may help control appetite and modestly boost fat burning. This data also adds to a growing body of research showing that meal timing matters. Other research suggests that eating in line with our body’s natural circadian rhythms may help with weight control. Your body is primed to take in and process calories early in the day and at times you’re most active and less so at night. In fact, insulin sensitivity is highest earlier in the day when you’re most active.
What about Weight Loss?
Preliminarily, small studies suggest that eating within a narrow time frame may help you eat less, but will this lead to weight loss? One study of 420 individuals who were trying to lose found those who ate their major meal of the day before 3:00 p.m. lost more weight than those who ate it after this time.
Another study found that participants who ate an equivalent number of calories but ate 50% more of those calories at breakfast as opposed to dinner experienced almost twice the weight loss of those who ate more calories at dinner. Metabolic measures such as triglycerides and insulin levels were also better in participants who ate more of their calories at breakfast.
There may be other health benefits to eating the big meal of the day earlier. A study found that eating dinner within two hours of bedtime was linked with a greater risk of cardiovascular disease. This isn’t surprising when you consider that insulin sensitivity is lowest at night. Participants who ate before bedtime had higher blood sugar and lipid levels.
Apply It to Your Own Life
How can you put these findings into practice? Make breakfast your largest meal of the day. Include a healthy source of protein to further increase satiety and help you stay satisfied. Lighten up on lunch and make dinner the lightest meal of all. It’s better for your metabolic health if you eat your largest meal when insulin sensitivity is greatest. Eat your final meal as early as possible and avoid snacking after dinner. Instead, relax with a cup of unsweetened chamomile tea in the evening to relax and unwind.
The Bottom Line
It’s hard to say whether these results apply to people of all ages and both genders. There simply isn’t enough research to draw firm conclusions. Yet, based on circadian rhythms and the pattern of hormone release based on time of day, it makes sense that eating more calories early in the day and limiting food intake before bedtime would be most beneficial. You can always start by making a small shift in the time of your meals. Eat dinner an hour earlier and gradually move dinnertime back as much as you can and still make it work with your lifestyle. But don’t forget! What you eat still matters too. The foods you put on your plate determine the nutrients that go into your body. Choose whole, unprocessed foods with a balanced array of macronutrients. If possible, take a 10-minute walk after every meal to help your body process glucose. Studies show that a 10-minute walk after every meal is more effective than a single 30-minute walk for blood glucose control.
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