Study: Large Breakfast vs. Large Dinner for Weight Loss. Does It Matter?
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Obesity is an epidemic that’s not resolving anytime soon. It affects 42% of US adults and increases the risk of diabetes, cardiovascular disease, metabolic syndrome, inflammatory conditions, dementia, cancer and early death. Many people seek weight loss to improve quality and length of life (health span and life span, respectively), as well as to decrease their healthcare costs.
Obesity-related research plays a large role in identifying efficacious weight loss and weight-loss maintenance strategies, as well as helping to guide clinicians and patient care. A 2013 study explored whether time of day and calorie intake influenced weight loss efforts over a 12-week period.
Ninety-three overweight/obese women with metabolic syndrome but without any other serious medical conditions were followed.
Participants were randomized into one of two groups: high-calorie breakfast (BF) or high-calorie dinner (D). Regardless of group, each woman was instructed to follow a 1400-calorie weight loss diet – high protein (41%), low carb (32%) - and was provided coordinating meal plans.
The BF meal plan provided: a 700-calorie high-protein (54g) breakfast, a 500-calorie lunch and a 200-calorie dinner.
The D meal plan provided the opposite: a 200-calorie breakfast, a 500-calorie lunch, and a 700-calorie high-protein (54g) dinner.
Those who did not comply with the specified calorie and meal requirements at a weekly average of 42.9% or above (or about 3 days a week) were withdrawn from the study.
Measurements such as blood pressure and weight were recorded every two weeks, whereas waist circumference was obtained at baseline, week 6 and week 12. Blood biomarkers - serum glucose, insulin, lipids, and plasma ghrelin - were obtained at baseline and 12 weeks.
Dropout rates mainly due to noncompliance were higher in the D group, possibly indicating less sustainability of that calorie-time distribution.
Both groups lost weight, however, the high-calorie breakfast eaters (BF) lost significantly more than the D group, 19 and 8 pounds, respectively – a 2.5-fold increase for the BF eaters. Waist circumference was also reduced more in the BF group. Blood pressure improved similarly in both groups.
Biomarkers also improved more in the BF group. Triglyceride levels improved by 33% in the BF group whereas they increased by 13% in the D group. Fasting glucose, insulin, and HOMA-IR – a marker of insulin sensitivity – all showed more significant improvements in the BF group.
Why and How Does This Work?
Mechanisms that explain biological advantages for a larger, high-calorie, high-protein breakfast and smaller dinner include: circadian rhythms, biological clocks affected by food intake, improved insulin sensitivity in the morning, delayed lipolysis (fat breakdown) in breakfast skippers, and the ability for breakfast protein to reduce hunger hormones and extend feelings of fullness.
A 2015 study highlighted that regular breakfast-eating women who start to breakfast skip show signs of worsened metabolic responses to lunch and metabolic dysfunction. This may have played a role in the metabolic disadvantages seen in the D group women.
How do you reconcile this insight if you want to follow a time-restricted feeding schedule? Eat a later breakfast (9am-ish was the latest allowed breakfast time in the study) like a king and dinner like a pauper, but still make it an early dinner (before 7pm-ish) so your eating window is shortened.
Evening exercisers? These active individuals likely experience less metabolic dysfunction from eating large meals later in the day than those who are sedentary.
Metabolically healthy and not overweight/obese? While you may not need or benefit from a tiny meal at dinner, not eating 2-3 hours before bed is still a solid piece of advice for most people. :)
According to these findings, consuming a large high-protein breakfast + a small dinner rather than a small breakfast + large high-protein dinner is a more effective strategy for both weight loss and improved metabolic health, at least in metabolically unhealthy women.
I for sure have seen both personally and professionally that the sure way to increase your potential for weight gain is to EAT A LOT OF JUNK AT NIGHT. This seems especially true the closer it is to your bedtime.
Can't give up your hearty dinner? Enjoy an active lifestyle and track your weight and metabolic health (i.e. fasting insulin, glucose, A1c, inflammatory markers) to make sure you're where you want to be and preventing chronic diseases. Reach out for lab work - I can order what you need checked and you can get them done at a lab near you!