Does food timing matter? Why eating more calories at night increases body fat.

Personal training constantly debate the idea that "a calorie is a calorie" and you need to "eat less to lose weight." Many people still believe that the only way to lose weight is to "eat less and move more."

But what if there was more than one way to lose weight?

What if you didn't need to cut calories and eat less?

Earlier this year, I did some research into protein intake demands for recreational athletes and their goals. Several studies showed an increase in protein intake, between 2.3-4.4g/KG of body weight, resulted in an increase in fat-free mass and a decrease in body fat.

A 2015 study took 48 healthy resistance-trained men and women and split them into a normal protein group (2.3g per Kg) and a high protein group(3.4g per Kg). The study lasted 8-weeks, and all participants followed a heavy split routine resistance program five days per week.  The high protein group was also on a surplus of total calories. 

The high protein group lost more fat mass and improved their body composition.  Both groups gained strength, improved the vertical jump and the total number of pull-ups.  The study concluded, "consuming a high protein diet (3.4 g per Kg) in conjunction with a heavy resistance-training program may confer benefits with regards to body composition."

Instead of telling our clients to eat less, we could ask them if they are willing to experiment with eat more, as long as their protein intake was high and they perform resistance training multiple times a week.

But is there another way to lose weight without cutting calories?

A 2017 study, "Later circadian timing of food intake is associated with increased body fat", examined the relations between the timing of food consumption and body composition.

110 participants, aged 18–22y, in a cross-sectional study to document sleep and circadian behaviours within their regular daily routines.

For 7 consecutive days, participants were asked to record all food and beverages they consumed, except water, by using the mobile phone application. Participants also had their body composition and melatonin release levels measured.

Side note: Melatonin is a hormone that we release in the evening that helps us sleep.

All of the participants ate breakfast, lunch, snacks, and dinner at roughly the same time.

They found that the people who had the highest body fat consumed most of their calories later in the day (close to melatonin release).

No relations were found between the clock hour of food intake, caloric amount, meal macronutrient composition, activity or exercise level, or sleep duration and either of these body composition measures.

The researchers concluded that "the timing of food intake relative to melatonin onset was significantly associated with the percentage of body fat and body mass index."

They went on to say, "a potential mechanism for increased body fat in response to later meal timing may be a decreased thermic effect of food, which is the energy expended in response to a meal."

Thus, one possible consequence of eating more calories in the evening may be a lower thermic effect response, contributing to a positive energy balance and weight gain over time.

These results provide evidence that food consumption during the circadian evening and/or night, independent of more traditional risk factors such as amount or content of food intake and activity level, plays an important role in body composition.

More and more people are jumping on the intermittent fasting (IF) bandwagon and skipping breakfast.  What choice do they have but to increase their calorie intake later in the day?  Could this actually be making them store more body fat?

An interesting experiment that personal trainers could suggest to weight loss clients would be skipping dinner. The health benefit of IF are well documented, and it makes more sense to skip the evening meal because the energy demands of sleeping are far less than the energy demands of our waking hours.

Eating a big breakfast (preferably high in protein), a medium-sized lunch and a small dinner is also a valid option. 

Its food for thought!