Do you struggle with being overweight? When you eat can be as important as what you eat. Many of your body clocks run over 24-hour cycles or circadian rhythms. Your body clocks help to govern your metabolism. Time-restricted feeding is a regimen that allows for eating only during a specific period in the normal circadian feeding cycle. It definitely improves your metabolism. Time-restricted feeding (TRF), during which access to food is restricted to a few hours (without caloric restriction), not only supports robust metabolic health but it helps to protect us from obesity.1 How?
Rodent studies show that feeding at an unusual time of the day (in what should be the inactive phase) desynchronizes our body clocks and causes obesity and metabolic disorders (prediabetes and diabetes). For example, staying up late and eating when we should be sleeping causes us to be hungry, encourages physical inactivity, and promotes fat accumulation in the liver. It also causes leptin resistance. Leptin is an important hormone involved in satiety. When leptin binds to leptin receptors in the hypothalamus, appetite is easier to control. Eating at unusual times of the day interferes with the ability of leptin to bind to its receptors and consequently, overeating becomes more likely. All this shows that untimely eating works havoc on our metabolism!2 If you want to control appetite and lose weight, avoid erratic times of eating (including snacks).3
Unfortunately, menopause is associated with significant hormonal changes that result in increased total body fat and abdominal fat, amplifying the risk for metabolic syndrome and diseases such as diabetes, cardiovascular disease, and cancer in postmenopausal women. Scientists have demonstrated that time-restricted eating, regardless of calorie consumption, can improve weight loss, reduce fat storage in the liver, and improve glucose levels in rodents who had metabolic disorders. In this case, rats had access to their high fat chow for only eight hours a day.4 It is also important to note that consumption of a high fat diet impairs metabolism. In other words, time restricted eating can offset some of the adverse effects of a bad diet!
How About Humans?
A time-restricted eating schedule in which all calories are consumed in an 8-hour window each day, coupled with resistance exercises, decreases fat mass and maintains muscle mass.5 But it gets even better! Eating early in the day reduces the swings in hunger, improves the ability of cellular powerhouses to burn fat, and aids energy metabolism in obese individuals. 6 All of this could help weight loss. This particular study showed that eating between 8 a.m. and 2 p.m., followed by an 18-hour daily fast, kept appetite levels more even throughout the day, in comparison to eating between 8 a.m. and 8 p.m., which is what the average American does. Guess what. Wildwood Lifestyle Center has been prescribing this program for over 55 years!
- Zarrinpar A. Daily Eating Patterns and Their Impact on Health and Disease. Trends Endocrinol Metab. 2016 Feb; 27(2):69-83.
- Yasumoto Y. Short-term feeding at the wrong time is sufficient to desynchronize peripheral clocks and induce obesity with hyperphagia, physical inactivity, and metabolic disorders in mice. Metabolism. 2016 May; 65(5):714-27.
- Manoogian EN. Circadian rhythms, time-restricted feeding, and healthy aging. Ageing Res Rev. 2016 Dec 23.
- Chung H. Time-restricted feeding improves insulin resistance and hepatic steatosis in a mouse model of postmenopausal obesity. Metabolism. 2016 Dec; 65(12):1743-1754.
- Moro T. Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. J Transl Med. 2016 Oct 13; 14(1):290.
- University of Alabama at Birmingham. “Time-restricted feeding study shows promise in helping people shed body fat.” ScienceDaily. ScienceDaily, 6 January 2017. <www.sciencedaily.com/releases/2017/01/170106113820.htm>.