Researchers from Brigham and Women’s Hospital (BWH) found that late eating increases our appetite and obesity risk, and also affects our energy expenditure and molecular pathways in adipose tissue (fat). Studies have highlighted the simultaneous effects of late eating on the three main players in body weight regulation and obesity risk: regulation of calorie intake, the number of calories burnt, and molecular changes in fat tissue. 

“…late eating is associated with increased obesity risk, increased body fat, and impaired weight loss success. We wanted to understand why,” said Dr. Frank Scheer, Director of the Medical Chronobiology Program in the Brigham’s Division of Sleep and Circadian Disorders. 

According to the latest research, eating later – by four hours – makes a significant difference for our hunger levels, the way we burn calories after we eat, and the way we store fat, revealed Nina Vujovic, a postdoctorate researcher in the same Program at BWH. 

Vujovic, Scheer, and their team studied 16 patients with a body mass index (BMI) in the overweight or obese range. Each participant completed two laboratory protocols: one with a strictly scheduled early meal schedule, and the other with the exact same meals, each scheduled about four hours later in the day. In the last two to three weeks before starting each of the in-laboratory protocols, participants maintained fixed sleep and wake schedules, and in the final three days before entering the laboratory, they strictly followed identical diets and meal schedules at home.  

In the lab, participants regularly documented their hunger and appetite, provided frequent small blood samples throughout the day, and had their body temperature and energy expenditure measured. To measure how eating time affected molecular pathways involved in adipogenesis, or how the body stores fat, investigators collected biopsies of adipose tissue from a subset of participants during laboratory testing in both the early and late eating protocols, to enable comparison of gene expression patterns/levels between these two eating conditions. 

Results revealed that eating later had profound effects on hunger and appetite-regulating hormones leptin and ghrelin, which influence our drive to eat. Specifically, levels of the hormone leptin, which signals satiety, were decreased across the 24 hours in the late eating condition compared to the early eating conditions. When participants ate later, they also burned calories at a slower rate and exhibited adipose tissue gene expression towards increased adipogenesis and decreased lipolysis, which promote fat growth.  

The findings convey converging physiological and molecular mechanisms underlying the correlation between late eating and increased obesity risk. 

By tightly controlling for behavioural and environmental factors such as physical activity, posture, sleep, and light exposure, the researchers were able to detect changes in the different control systems involved in energy balance, a marker of how our bodies use the food we consume – however, in real life, many of these factors may themselves be influenced by meal timing, the researchers note. 

Here are five simple ways to avoid mindless eating and lay off the extra calories

1.       Listen to your body’s signals

Listening to the body’s hunger signals and only eating at those times is one way to becoming more mindful of your eating patterns. When you’re in the middle of a meal, pay attention to when you’re feeling full. It’s easy to overeat when dining with others, eating out or eating at someone else’s home because everyone else is eating too, or because you want to be polite and finish everything on your plate. In reality, the healthiest thing to do is to stop eating when you’re feeling full.

Pay attention to your body. It will let you know when you have reached the satiety point. You can always get your leftovers to go or place them in the fridge for the next day.

2.       Eat only when you are hungry

Eating only when your body tells you that you are hungry is important to avoid mindless eating. It is common for people to eat when they are bored, stressed out or feeling sad. This is known as emotional eating and is a pattern that can lead to overeating or eating too much of the wrong foods. The best way to combat emotional eating is to check in with yourself on a regular basis to be sure that you’re eating because you’re hungry.

3.       Replace emotional eating with another activity

When you do realize that you are eating because of an emotional need, think of another activity that will make you feel better. For example, instead of eating chocolate or a bag of potato chips, maybe go for a walk, call a supportive friend or family member, write a journal, listen to your favorite music or meditate. Exercise is also a great activity to replace emotional eating as it enhances the mood and burns up extra calories.

4.       Avoid set meal time

One way to avoid mindless eating is to be flexible in your meal times. Sometimes you don’t have a choice because your work schedule demands that you take a lunch break at a set time. However, when you do have a choice, for example, at dinner time or on the weekends, avoid eating by the clock. Eating at set times is problematic because you are on automatic. You are not reaching for food because you are necessarily hungry. You are eating because others are eating or because you think you should be eating.

5.       Enjoy your food

A modern, fast-paced life makes it easy for people to rush through meals or eat them on the go. When you sit down to eat, really tune into the tastes, smells and texture of your food. Eat slowly. Chew your food enough. Some foods taste better the longer you chew them. Chewing your food enough is also very important and healthy for your digestive system.