UK surgeon reveals why early calorie intake boosts weight loss

While weight loss is often linked to maintaining a calorie deficit, experts say the timing of meals can significantly influence how the body processes food and burns fat. 

According to UK-based surgeon Dr Karan Rajan, when you eat may be just as important as what you eat.

Sharing insights from a 2013 clinical study, Dr Rajan explained that two groups of overweight women followed identical diets of 1,400 calories per day over 12 weeks.

However, the distribution of calories differed. One group consumed the majority of their calories earlier in the day, starting with a large breakfast, while the other group ate most of their calories in the evening.

The results showed a striking difference. Participants who ate a calorie-heavy breakfast lost significantly more weight and saw greater reductions in waist size compared to those who consumed larger dinners, despite both groups eating the same total number of calories.

Dr Rajan highlighted that the body is naturally better equipped to process food earlier in the day. 

Insulin sensitivity — the body’s ability to manage blood sugar — is higher in the morning, allowing for more efficient energy use. 

Digestive processes, including enzyme activity and gut movement, are also more active earlier, supporting better metabolism.

Additionally, the gut microbiome is thought to function more efficiently during the day, further aiding digestion and energy balance.

Experts say aligning food intake with the body’s natural rhythm may improve metabolic health. 

A pattern of a larger breakfast, moderate lunch and lighter dinner could support weight management, though overall calorie intake still remains a key factor.