Could the timing of our meals be as important to our ability to lose or maintain weight as what we are eating? Chrononutrition or meal timing is based on the idea that the body's natural circadian rhythms play a key role in digestion and metabolism. The theory behind chrononutrition is that eating at specific times of the day can optimize your body's ability to digest and process food, leading to better weight management and overall health.
The main principles involve eating a balanced diet of whole, nutrient-dense foods, with an emphasis on consuming more calories earlier in the day and fewer calories later in the day, as well as closing the eating window at least 2-3 hours prior to bed. This approach is based on the idea that the body is better able to process calories, especially carbohydrates and protein, in the morning and early afternoon when you are most insulin sensitive and able to digest foods thoroughly and utilize that food. Eating larger meals later in the day has been shown to lead to weight gain possibly due to lower insulin sensitivity and a decrease in the likelihood of using those calories for energy prior to going to sleep. Weight loss methods mainly aim at reducing dietary energy intake and/or increasing energy expenditure via physical activity, with little or no emphasis placed on details such as meal timing.
According to this recent study ( Improvement in chrono-nutrition is associated with robust weight loss outcomes: An extension of the feasibility study - PubMed (nih.gov) which consisted of a 12-week chrononutrition (meal timing) based integrative weight loss program.
The meal plans focused on daily caloric intake, macronutrient distribution at each meal and throughout the day as well as meal times. For example, some participants were instructed to consume 75% of their calories in the early window of the day (i.e., breakfast, morning snack, and lunch), whereas other participants were instructed to consume only 60% of their calories in the early window of the day, meaning that they consumed more calories later in the day.
The study found that the participants who lost a significant amount of weight consumed more protein in the early window, ate less fat during the late window and had a shorter daily eating window overall. Additionally, their last meal of the day was consumed earlier than the participants who did not lose significant weight.
It has also been shown that skipping breakfast and eating late can have a negative effect on blood sugar control and BMI (body mass index). In this study, (The Effect of Breakfast Skipping and Late Night Eating on Body Mass Index and Glycemic Control Among Patients With Type 2 Diabetes Mellitus - PubMed (nih.gov) 45% of the participants skipped breakfast, and 20% reported eating late at night. There is an association between a higher BMI and skipping breakfast. Eating late at night was also correlated with higher BMI and higher overall blood sugar levels. Why would they look at blood sugar? Blood sugar control is an important indicator of overall metabolic health and not only is it a predictor of developing diabetes, but if blood sugar is high this means your insulin levels are high. And you cannot burn fat if your insulin is high.
Overall, eating later increases the odds of being hungry compared to eating earlier due to fluctuations in hunger and satiety hormones. Eating later has been shown to decrease leptin levels by 16% (Leptin is the hormone that promotes satiety or your sense of feeling full) during the hours we are awake and increased the ghrelin:leptin ratio by 34%. Ghrelin is your hunger hormone. So, this in effect shows that you will feel more hunger and have a decreased sense of fullness when you shift your eating window to later in the day. Eating later can also decrease your energy expenditure by lowering your average core body temperature as well as decreasing the efficiency of several genes responsible for fat breakdown and increasing several genes responsible for fat development.
What are the key takeaways?
· Shift your eating window to earlier in the day.
· Ensure you are getting adequate protein, especially earlier in the day. Strive for at least 30 grams of protein per meal.
· You may be at an increased ability to metabolize and utilize carbohydrates in the first part of the day.
· Ensure you close your eating window at least 2-3 hours before you go to bed.
· Avoid eating heavy carbohydrates or fatty meals late in the day.
· Get sunlight 1st thing in the morning to line up your circadian rhythm to sync your body and its hormones with the natural metabolic flow of the day.
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Need help with Protein? Grab these high-protein recipes which are an example of how to reach your protein goals!
Disclaimer: The purpose of this blog post is not to act as a personal healthcare professional to any reader and is not meant to directly or indirectly diagnose disease, dispense medical advice, or prescribe the use of any products or services as treatment for sickness or disease. This information is for educational purposes only. You should always cooperate with a licensed health professional of your choice to create optimal health. Please consult your physician before implementing any of the strategies mentioned in this or starting any diet, exercise, or health program—especially if you are pregnant or nursing. Any application or use of the information, resources, or recommendations contained here is at your own ris