Chrononutrition consists of planning our meals according to our biological clock, which is called the circadian rhythm. It could help us better manage our energy, weight, and well-being.
Our current lifestyles, with skipped or late meals, snacking, stress, and sedentary behavior, disrupt our biological clock.
These disruptions promote obesity and overweight, which in turn disrupt the internal clock. We enter a vicious circle!
But it is possible to reverse the trend, notably thanks to chrononutrition. Because a rhythmic diet and structured meals help limit insulin resistance, fat mass gain, and obesity. I explain here how it works and dissect the studies on the subject.
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Understanding chrononutrition
The principle
Chrononutrition was developed in 1986 by Dr. Alain Delabos, a medical nutritionist, based on the work of Professor Jean-Robert Rapin on biological rhythms.
In chrononutrition, we eat at regular times and adapt what we eat to the time of day. The idea is that our body does not process food the same way in the morning, at midday, or in the evening.
Following the body’s rhythm
Our body operates on a circadian rhythm, that is an internal clock that lasts about 24 hours, based on the day/night cycle. This rhythm influences our sleep, our energy, and the production of certain hormones:
- In the morning, cortisol (the stress hormone) rises and promotes wakefulness and alertness
- In the evening, melatonin takes over to promote sleep
Eating at regular times helps to adapt to these hormonal secretions.
How and when to eat?
Morning
Opt for a hearty breakfast, rich in protein (eggs or cheese, for example) and fats. Proteins stimulate dopamine production, which boosts motivation.
I recommend adding a source of carbohydrates, for example whole-grain bread, to limit daytime hunger. The presence of carbohydrates at breakfast reduces the secretion of ghrelin, the hunger hormone.
Midday
Opt for a serving of whole grains or legumes, accompanied by vegetables and a source of protein. I note that in chrononutrition it is recommended not to consume a sugary dessert, but to save it for a snack.
Snack
It’s time for a sweet touch! Preferably unrefined sugars, such as a piece of fruit. I recommend pairing it with nuts to make it more filling: almonds, walnuts, hazelnuts, as a purée for extra indulgence.
Dinner
In the evening, Dr. Delabos recommends a light dinner composed of vegetables and proteins to promote good sleep.
However, several studies show that consuming a small portion of carbohydrates can improve sleep quality and reduce the risk of insomnia. I therefore recommend choosing low glycemic index carbohydrates, for example quinoa, brown rice, whole-wheat al dente pasta, sweet potato… accompanied by vegetables for their fiber content.
In contrast, this study shows that a dinner that is too late (less than one hour before bedtime) and high in carbohydrates can raise blood glucose after the meal, and even the next morning’s blood glucose. This is explained by a slowdown in metabolism during sleep and less effective fat breakdown.
So opt for a dinner high in fiber with a small portion of complex carbohydrates, vegetables, and protein, at least four hours before bedtime.
The effects of chrononutrition on health
Health benefits
Chrononutrition helps limit blood sugar spikes, which is beneficial for people with type 2 diabetes. It also reduces gain in body fat, especially in cases of overweight or obesity. For this, its important to eat dinner at least four hours before bedtime.
Cambridge University Press published a study on this topic. In a clinical trial, overweight or obese women following a hypocaloric diet were assigned to an early-dinner group or a late-dinner group.
The group that ate earlier lost more weight and showed better indicators of carbohydrate metabolism.
Be careful about restrictions
The principle of chrononutrition, as presented by Dr. Delabos, remains fairly strict, with certain foods forbidden (milk, yogurts, soup…), which can give the impression of a restrictive diet.
I often observe in my patients the harmful consequences of an overly restrictive diet, which is why I recommend not banning foods, but rather consuming them in moderation.
My opinion on chrononutrition
Chrononutrition: yes, but without restrictions
Chrononutrition as it can be practiced today should be more flexible and personalized. If you want to get started with chrononutrition, I think you need to find a compromise. By respecting your biological clock without being too restrictive, I suggest composing your day as follows:
- Breakfast: favor protein, whole-grain starches, and a touch of fat (coconut oil in coffee, for example)
- Lunch: whole-grain starches, vegetables, and protein
- Snack: a piece of fruit and a few nuts (walnuts, hazelnuts, almonds)
- Dinner: vegetables, protein, and a small portion of whole-grain starches (we don’t eliminate anything, we just adapt!)
A diet adapted to your lifestyle
We all have different life rhythms, it’s important to listen to your needs. Chrononutrition can be difficult to implement depending on lifestyle, particularly in the case of irregular work hours.
In that case, I recommend adjusting meals according to wake and sleep times: a night worker will have breakfast upon waking, lunch at the end of the day, and dinner during the night.
Finally, I think thatthere is no universally ideal diet: the best diet is one that respects health while adapting to each person and their lifestyle.
Sources and scientific studies
1. Marica Franzago, Elisa Alessandrelli, Stefania Notarangelo, Liborio Stuppia, and Ester Vitacolonna. Chrono-Nutrition: Circadian Rhythm and Personalized Nutrition. [Online] January 29, 2023
2. Konstantinos Mantantzis, Vanessa Campos, Christian Darimont, Francois-Pierre Martin. Effects of Dietary Carbohydrate Profile on Nocturnal Metabolism, Sleep, and Wellbeing: A Review. [Online] July 13, 2022
3. Chenjuan Gu, Nga Brereton, Amy Schweitzer, Matthew Cotter, Daisy Duan, Elisabet Børsheim, Robert R Wolfe, Luu V Pham, Vsevolod Y Polotsky, Jonathan C. Metabolic Effects of Late Dinner in Healthy Volunteers-A Randomized Crossover Clinical Trial. [Online] June 11, 2020
4. Elizabeth A. Thomas, Adnin Zaman, Marc-André Cornier, Victoria A. Catenacci, Emma J. Tussey, Laura Grau, Jaron Arbet, Josiane L. Broussard and Corey A. Rynders. Later Meal and Sleep Timing Predicts Higher Percent Body Fat. [Online] December 29, 2020
