Eating a big breakfast and a small dinner, or pushing your calories back to earlier in the day, leads to lower blood sugars throughout the day compared to eating most of your food at night. That’s what this new study found:
Conclusions/interpretation: High energy intake at breakfast is associated with significant reduction in overall PPHG* in diabetic patients over the entire day. This dietary adjustment may have a therapeutic advantage for the achievement of optimal metabolic control and may have the potential for being preventive for cardiovascular and other complications of type 2 diabetes.
* PPHG: Postprandial hyperglycemia, high blood glucose after eating.
It used a crossover design so subjects were randomized to one diet for 7 days then switched to the other diet for 7 days. Diets had the same number of calories, same carb/fat/protein amounts; they differed only by time of day eaten.
The big-breakfast diet (Bdiet) provided these calories per meal, the big-dinner diet (Ddiet) was reversed:
- 2946 kj (~704 kcal) breakfast (8:00 am)
- 2523 kj (~603 kcal) lunch (1:00 pm)
- 858 kj (~205 kcal) dinner (7:00 pm)
From the chart below… Glucose was higher after breakfast in the big-breakfast (Bdiet) group, but was considerably lower after lunch and dinner, such that the total glucose roaming the bloodstream during the day, shown by the total area under the curve (AUC), was significantly lower in the Bdiet group.
The lunch meals were exactly the same, but:
Despite the diets being isoenergetic, lunch resulted in lower glucose (by 21–25%) and higher insulin (by 23%) with the Bdiet vs Ddiet.
How does this happen?
This is achieved in part by the circadian secretion and activity of enzymes and hormones involved in the regulation of postprandial glycaemia [9–13].
Also from their literature review:
The omission of breakfast was also associated with increased risk of type 2 diabetes, poor glycaemic control, higher HbA1c, increased lipogenesis, visceral adiposity and high blood pressure and increased cardiovascular risk despite the same daily energy intake in individuals with type 2 diabetes [20,21].
These were not whole food, plant-based meals. Indeed, there was animal food at least 7 times a day (tuna, egg, yogurt, milk, chicken, cheese, turkey). (Would you consider this eating animal food in moderation?) But since each person acted as their own control, and the foods were held constant, it does shed light on the effects of timing vs. content.
This study, since it focuses more on when to eat instead of what to eat, reminds me of the study in this post: Limiting Eating To 8-12 Hour Period Causes Weight Loss, Diabetes Reversal In Mice.