Should Breakfast be the Largest Meal of the Day?

Every year is unfortunately full of new and unproven “fad” diets. One of the more recent fads is intermittent fasting (IF), which results in skipping breakfast. There are many variations of IF and the current belief (after hundreds of studies on IF) is that intermittent fasting is at best equal to standard dieting, but it surely has not been proven to be better. It was believed that there was something metabolically advantageous to a fasting.

The version of IF that seems to have become most popular is a six to eight hour eating window and a 16 to 18 hour fasting window. The timing variation most popular is to skip breakfast and start eating from 12 to 2 in the afternoon and stop by 8 pm.

A recent small study was published on 30 patients (16 men and 14 women), average age 51 and BMI between 27 and 42 (meaning they had overweight or obesity). The study lasted for two four-week sessions. In the first session, breakfast was the largest meal (45% of calories at breakfast, 35% at lunch and 20% at dinner) and in the second session dinner was the largest meal (20% of calories at breakfast, 35% at lunch and 45% at dinner). For both diets, all meals were completely provided to the study participants and comprised 30% protein, 35% carbs and 35% fat.

It is interesting but not surprising to see that both groups lost about the same weight of 6.6 lbs. There was no change in metabolism in either group BUT the large breakfast group had less hunger experienced throughout the day.

The study was short at 2 months in total and all food was provided so both groups successfully lost weight. If your goal is to lose weight and keep it off, hunger is important and therefore so is a good breakfast. Mom was right, breakfast is the most important meal of the day!

Source: https://doi.org/10.1016/j.cmet.2022.08.001