Chrononutrition: eat in tune with your circadian rhythm

Published: 14/10/2024 | Author: Isabella Lee, PhL., Nutritionist

Chrononutrition, the study of how our eating patterns align with our body’s internal clock, has gained increasing attention in recent years. This field of research emphasises the importance of not just what we eat, but when we eat, and how this timing can significantly impact overall health. For women, whose biological rhythms are influenced by hormonal fluctuations throughout life, chrononutrition offers a promising avenue for enhancing wellbeing and overall health.

Why meal timing matters

Our bodies operate on a 24-hour cycle known as the circadian rhythm, which governs various physiological processes, including metabolism, digestion and hormone production. This rhythm is not only influenced by external cues like light and dark exposure, but also food intake, making meal timing a critical factor to maintain metabolic health. In fact, research has shown that the timing of meals has an even greater influence on physiological processes than the signals coming from the brain’s main biological clock.

Our biological rhythms influence how our body’s process nutrients and this varies throughout the day. For instance, insulin sensitivity is higher in the morning, which means the body is better equipped to manage blood sugar levels after breakfast. Research suggests that front-loading calories earlier in the day – consuming a larger breakfast and a smaller dinner – therefore aligns better with our circadian rhythms. On the other hand, eating at irregular times or late at night can disrupt our circadian rhythms, which can increase the risk of metabolic disorders like obesity, type 2 diabetes, and cardiovascular disease.

Chrononutrition and women's health

Women experience unique physiological changes throughout their lives, including menstruation, pregnancy, and menopause, all of which can influence circadian rhythms and metabolic health. Chrononutrition can play an important role in facilitating these changes.

Menstrual cycle: Hormonal fluctuations during the menstrual cycle affect appetite, energy levels, and metabolism. For example, during the luteal phase (post-ovulation), women may experience PMS symptoms (like cramps and fatigue) and increased cravings. During this phase, both the energy expenditure and energy intake is usually higher than during the follicular phase (menstruation). Synchronising mealtimes with these hormonal shifts may help manage weight and energy levels.

Pregnancy: During pregnancy, circadian rhythms can be disrupted, affecting both maternal and fetal health. Studies suggest that irregular mealtimes and late-night eating may contribute to gestational diabetes and excessive weight gain. Pregnant women may benefit from structured meal timing that aligns with their natural circadian rhythms to support a healthy pregnancy.

Menopause: As women approach menopause, changes in estrogen levels can disrupt circadian rhythms, leading to sleep disturbances, weight gain, and insulin resistance. It is well known that the fall in estrogen levels, but also the resulting vasomotor symptoms, directly impacts the sleep-wake cycle. Chrononutrition strategies, such as time-restricted eating, may help mitigate these effects by improving metabolic health and enhancing sleep quality.

How to eat according to your circadian rhythm

Prioritise breakfast: Aim to consume a balanced, nutrient-dense breakfast that is high in protein (approx. 25-30g). This will provide sustained energy throughout the day, which is particularly beneficial for women experiencing energy dips or sugar cravings later in the day. Protein also helps to maintain muscle mass and promote fat loss, which has a direct impact on metabolism and hormonal levels.

Introduce time-restricted eating: Time-restricted eating limits the eating window to 8-12 hours a day, allowing the body to fast for the remaining 12-16 hours. For example, a 10-hour eating window can be between 08:00 – 18:00. Fasting should take place during the early evening and night for optimal alignment with our circadian rhythms. This approach has been shown to improve metabolic markers, support weight loss, and enhance insulin sensitivity, which can be especially helpful for women in managing hormonal changes.

Avoid late night eating: Eating should be minimised late in the evening to align with the body’s natural decline in metabolism. In the evening, our melatonin levels rise, which makes us feel sleepy, but it also decreases our ability to process simple carbohydrates. Make the last meal of the day high in protein and dietary fibre for optimal metabolic response and sleep quality. Late-night eating has been linked to weight gain and poor glycaemic control, particularly in postmenopausal women.

Adjust nutrition to hormonal phases: Women can benefit from adjusting their diet and meal timing according to their menstrual cycle. For example, increasing protein and healthy fats during the luteal phase (post-ovulation) may help stabilise mood and reduce cravings. Also, decreasing the caloric intake slightly during the follicular phase (pre-ovulation) may be a good strategy to help balance the increase later in the cycle.

Conclusion – the benefits of chrononutrition

Chrononutrition offers a personalised approach to health, recognising the importance of meal timing in relation to the body's natural rhythms. For women, who face unique hormonal and metabolic challenges throughout life, this approach can be particularly beneficial. By aligning eating patterns with the body's circadian rhythms, women can optimise their health, manage weight more effectively, and help reduce the risk of chronic disease, for wellbeing at every stage of life.

References

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Franzago M, Alessandrelli E, Notarangelo S, et al. Chrono-Nutrition: Circadian Rhythm and Personalized Nutrition. Int J Mol Sci. 2023 Jan 29;24(3):2571. doi: 10.3390/ijms24032571.

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