Large breakfast may aid weight loss but should it favor protein or fiber?

• New research suggests that, particularly for those trying to lose some weight, the old adage that breakfast is the most important meal of the day may be true.
• A small-scale study has found that people with overweight and obesity who followed a diet where they ate 45% of their daily calories for breakfast, and only 20% in the evening, lost weight.
• Effects varied with type of breakfast; those on a high-fiber plan lost slightly more weight and gained gut biodiversity, while those on a high-protein diet reported feeling less hungry, which could help with longer-term weight management.

When you eat, recent research suggests, may be as important for health and weight control, as what you eat, with evidence that eating later in the evening is associated with weight gain.

So should you eat a hearty breakfast instead of a large dinner?

A new study in adults with overweight and obesity suggests this could be advisable. Researchers found that eating a large, protein- or fiber-rich breakfast, and limiting energy intake in the evening was associated with weight loss.

The study, published in the British Journal of Nutrition, found that, while both groups lost weight, those in the protein-rich group experienced less hunger, and the fiber-rich diet led to slightly greater weight loss and an improvement in gut biodiversity.

Thomas M. Holland, MD, physician-scientist and assistant professor at the RUSH Institute for Healthy Aging, RUSH University, College of Health Sciences, who was not involved in this study, told Medical News Today:

“This was a randomized crossover trial, meaning participants served as their own controls, which strengthens internal validity and reduces variability between individuals. The investigators carefully controlled calorie intake relative to resting metabolic rate and measured detailed physiologic outcomes, including thermic effect of food, insulin resistance indices, and microbiome composition.”

“However,“ Holland cautioned, “the cohort was small and predominantly male, and each intervention lasted only 28 days, which limits broader application and long-term interpretation.“