Weight loss will always come down to calories in versus burned, also known as a calorie deficit, but this too can be complicated.
Someone who is always feeling hungry is likely to overeat, and the more you eat, the hungrier you will later become – and so the vicious cycle continues.
Previous studies have found a strong link between energy regulation and the circadian clock – but how to burn calories without it affecting your appetite remains unclear.
The circadian system is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours.
What also remains unknown is how daily energy distribution can influence the appetite hormones throughout the day.
The hunger hormone (ghrelin), for example, is suppressed more in response to a breakfast meal than the same meal provided in the evening.
Researchers are continuing to explore how eating at certain times could lead to better calorie disruption and therefore aid in belly fat loss.
The importance of metabolism
“Metabolism is the process by which your body converts what you eat and drink into energy,” explains the Mayo Clinic.
It adds: “During this complex process, calories in food and beverages are combined with oxygen to release the energy your body needs to function.”
This function is vital for weight loss and has three components which include:
Basal metabolic rate (BMR) which is the minimum calories the body utilises in a resting state for standard body functions.
Thermic effect of food (TEF) which is the energy needed to absorb, process, and store nutrients after you eat food.
When is the best time of day to eat for weight loss?
In the present study, researchers performed a four-week randomised controlled feeding trials comparing morning-loaded (ML) versus evening-loaded (EL) calorie intake.
The researchers distinguished the distinct area of metabolic function that contributed to differences in energy balance reported in prior studies.
The study involved 30 healthy but obese individuals with body mass index (BMI) between 27 and 42 kg/m2.
The team randomised 14 participants to the ML diet first and 16 to the EL diet first with similar total calorie and macronutrient intake.
The eating window was slightly longer across the day in the ML than in the EL diet (11:05 h vs. 10:39 h), with meals consumed relatively early in the day.
The research had several significant findings about the time of daily calorie intake.
Although ML and EL diets did not affect energy metabolism and resulted in similar weight loss in healthy obese individuals, ML calorie loading resulted in lower appetite and hunger, which explains the weight loss benefits of ML diets.
Researchers also found that the ML diet resulted in markedly lower average daily hunger, desire for food, prospective consumption, thirst, and composite appetite score.
They observed more significant appetite suppression with the ML diet was partially due to the extended duration of gastric emptying of the larger meal size and calorie load.
It concluded that hearty breakfasts or ML diet was more effectively for belly and weight loss by suppressing appetite.