Over two decades ago, a landmark study showed that participants who ate a large breakfast lost 10 pounds more than those who ate a smaller breakfast, even though both groups consumed the same amount of total calories per day. Other studies also showed that shifting food intake to earlier in the day increased weight loss. The reason is related to our circadian rhythm. Our circadian rhythm orchestrates metabolism over a 24-hour period defining ideal times for energy expenditure, appetite and insulin sensitivity. Unfortunately in today’s world with an unlimited supply of food and 24/7 work cycles, our lives are often totally out of sync with the genetic programming of our circadian rhythm.
A recent study reinforces the importance of the circadian rhythm to our metabolic health. The investigators evaluated whether eating earlier in the day so meals aligned to our natural circadian rhythm, would facilitate weight loss. Both groups in the study consumed the same total calories. One group consumed their calories between 8 am and 2 pm and the second between 8 am and 8 pm. The research found there was slightly less desire to eat in the group who consumed their calories early. There was also no decrease in energy levels.
However, the group who consumed their calories early in the day had an increase in fat metabolism. Thus eating your daily calories early in the day, especially during a weight loss program may offer multiple advantages. There is no increase in hunger, better appetite regulation and a greater utilization of fat for energy. The bottom line, aligning food consumption to our natural circadian rhythm confers additional metabolic benefits. Timing is everything.