When we aim to lose weight, we often hear the classic advice: “eat better” and “exercise more”. Undoubtedly, these two aspects are very important for achieving weight loss, but do you think that’s everything, or is there more?
The place where we are born and where we live, our culture, our parents’ habits, our work… are some of the factors that shape our daily routines. Within these routines, we find aspects such as the foods we eat, traditions, or other factors that can influence the time at which we have our meals.
The latest scientific evidence indicates that this aspect is also key to obtaining greater benefits when aiming for weight loss. This approach is known by its English terms “Food Timing” or “Clock Diet”.
How do meal times affect our weight loss?
Circadian rhythms or chronobiology are a field that studies how our sleep–wake cycles are regulated and which factors can affect them. Our circadian rhythms regulate and synchronize various aspects of our body, including the secretion of different hormones, physiological conditions, and sleep cycles. This internal clock is regulated by molecules known as “transcription factors” (which regulate gene expression), such as BMAL1, CLOCK, and NPAS, among others.
Two very important factors capable of governing these circadian rhythms are sleep and the times at which we eat. The regulation of these transcription factors, the genes involved in these rhythms, and the metabolic processes affected as a consequence are highly influenced by these factors. Several studies indicate that changes in meal timing, especially in people who are overweight or obese, can mark a turning point in the weight loss they aim to achieve. Not only that, but in healthy adults, failing to maintain consistent routines around sleep and meals can lead to metabolic dysfunction, increasing the risk of metabolic disorders. Some studies have even observed that maintaining this type of habit change in this population (without any other adjustment) can lead to weight loss of around 3.4%, which is maintained over time.
Several studies indicate that, in a large part of the population, it is necessary to bring forward lunch and dinner times to achieve the best possible results… but is that really true?
Is there a single formula that works for everyone?
The answer is clearly no. As we know, every person is different, and there are factors in daily routines that can strongly condition these aspects, such as night work or shift work, our chronotype, and, of course, our genetics — all of which break the typical “one-size-fits-all formula”. A person with a night-shift job has a melatonin secretion pattern — the hormone that regulates these cycles — that is completely different from someone who works during the day. They will not eat at the same times, sleep at the same times, or even be exposed to sunlight in the same way as a daytime worker.
Now let’s imagine two people who both work during the day — even then, the same formula does not apply to both. This is due to our chronotype: some people have different melatonin secretion patterns even when maintaining similar habits. Chronotype determines whether a person is more morning-oriented (larks), evening-oriented (owls), or somewhere in between. This means daily routines must be adapted to each chronotype not only to gain greater health benefits, but also better performance.
In addition, several scientific studies have identified mutations located in the transcription factors mentioned above (BMAL1, CLOCK, NPAS) that can significantly affect our circadian rhythms. These mutations can even interact with the intake of certain nutrients, representing yet another barrier to consider when adjusting sleep and eating habits to our chronobiology.
Ultimately, the greater our understanding of ourselves and the factors that affect our internal clock, the better we can regulate it and the greater the benefits we can obtain — not only in terms of weight loss, but also for our overall health.
References
- Allison KC, Goel N. Timing of eating in adults across the weight spectrum: Metabolic factors and potential circadian mechanisms. Physiol Behav. 2018 Aug 1;192:158-166. doi: 10.1016/j.physbeh.2018.02.047. Epub 2018 Feb 24. PMID: 29486170; PMCID: PMC6019166.
- Basolo A, Bechi Genzano S, Piaggi P, Krakoff J, Santini F. Energy Balance and Control of Body Weight: Possible Effects of Meal Timing and Circadian Rhythm Dysregulation. Nutrients. 2021 Sep 19;13(9):3276. doi: 10.3390/nu13093276. PMID: 34579152; PMCID: PMC8470941.
- Plano SA, Casiraghi LP, García Moro P, Paladino N, Golombek DA, Chiesa JJ. Circadian and Metabolic Effects of Light: Implications in Weight Homeostasis and Health. Front Neurol. 2017 Oct 19;8:558. doi: 10.3389/fneur.2017.00558. PMID: 29097992; PMCID: PMC5653694.
- Dashti HS, Scheer FAJL, Saxena R, Garaulet M. Timing of Food Intake: Identifying Contributing Factors to Design Effective Interventions. Adv Nutr. 2019 Jul 1;10(4):606-620. doi: 10.1093/advances/nmy131. PMID: 31046092; PMCID: PMC6628856.
- Barrea L, Frias-Toral E, Aprano S, Castellucci B, Pugliese G, Rodriguez-Veintimilla D, Vitale G, Gentilini D, Colao A, Savastano S, Muscogiuri G. The clock diet: a practical nutritional guide to manage obesity through chrononutrition. Minerva Med. 2022 Feb;113(1):172-188. doi: 10.23736/S0026-4806.21.07207-4. Epub 2021 Apr 29. PMID: 33913659.
