One of the most common questions I get asked is “When should I eat?“ It’s not as critical as you think, most of the time.
You’ve likely seen the eye-grabbing headlines streaming across your news feeds – “Why Food Experts Say Eat a Huge Breakfast to Lose Weight”, “Skip Breakfast to Lose Weight”, “Late Night Meals Make You Fat”, and “Stop Counting Calories, it’s the Clock that Counts”.
It’s confusing and may be tempting to treat these headlines as dogma. In reality, we have a great deal of flexibility regarding when we eat for desired results, and it is counterproductive to expend a disproportionately large amount of effort to hit some perceived perfect meal timing (versus prioritizing other variables). For healthy training adults who are seeking to improve energy, performance, and improve body composition, there are several primary factors to control in nutrition strategy. These are total daily energy intake, macronutrients (ensuring positive daily protein balance), and food selection. It is important to assess these factor as it relates to your goals, and this should be set before exploring nutrient timing. With that established, here are a few practical takeaways regarding meal timing and frequency based on current research and observational studies.
Seek consistent timing and distribution of meals every day. Yes, this includes weekends! [1]
Irregular eating patterns have an impact on the signaling in our central and peripheral circadian clocks; erratic eating patterns may result in reduction in basal metabolic rate, [2] reduced food thermogenesis (change in metabolic rate that occurs after a meal), and impaired glucose tolerance [3]. These factors are likely drivers for the association between irregular eating pattern, higher body mass index, and unfavorable cardiometabolic health. [4]
In terms of protein intake and body composition and muscle synthesis, there is likely a benefit to more frequent meals (4-5 per day) versus less frequent.
However, this impact appears minimal.[5] So, it’s probably beneficial to distribute your protein-based meals evenly throughout the day, but not at the expense of your ability to adhere to your program and overall satisfaction. For lean muscle mass retention and growth, it’s a good idea to eat high quality protein and rapidly digestible carbohydrate after a training session. This does not mean you need to chug a protein shake immediately after your last set – the anabolic window for muscle protein synthesis is wide. If you don’t have a protein snack or shake available after a workout, have a meal containing whole protein and carbohydrate within 2 hours of your training session.
Related to weight loss, there may be benefits to consuming a larger fraction of calories earlier in the day.
Some studies have indicated that consuming a greater proportion of nutrients earlier in the day is beneficial. This supports increased total daily energy expenditure and improved glucose response. [6,7,8] This does not mean wake up and immediately have a huge breakfast. Rather, try to eat more of your calories before mid-afternoon. There are strong caveats here for training individuals. For example, if you train in the evenings your muscles will be in a better position to dispose glucose from your bloodstream, whereas eating later in the day will not have as much of an impact. This is because as there is improved glycemic response post-exercise, regardless of time of day. [9]
Assuming you are eating the same number of calories per day, intermittent fasting appears to yield similar weight loss results as general calorie reduction [10,11].
Comparing diets of equal calories, there appears to be no benefit to intermittent fasting for more rapid weight loss versus eating in a more conventional time window. That said, many people have successfully lost weight with intermittent fasting versus general dieting because they eat fewer calories per day. So if weight loss is your goal, it may be worth experimenting with decreasing the time window in which you eat food as it may help you consume fewer calories per day.
With these takeaways, first and foremost is to consider what is practical and sustainable for you. This enables higher adherence, satisfaction from food, and optimizes energy and performance on a personal level. An ideal plan on paper is worthless if it is impossible to follow day in and day out. I strongly encourage everyone to experiment with meal timing and frequency in consideration of both short- and long-term goals.
Need some help establishing a nutrition strategy specific to YOUR goals? Contact me.
References:
[1] Zeron-Rugerio, M.F, Hernaez, A., et al. Eating Jet Lag: A Marker of the Variability in Meal Timing and Its Association with Body Mass Index. Nutrients 11, 2980 (2019).
[2] Farschi, H.R., Taylor, M.A., Macdonald, I.A. Beneficial Metabolic Effects of Regular Meal Frequency on Dietary thermogenesis, Insulin Sensitivity, and Fasting Lipid Profiles in Healthy Obese Women. Am J Clin Nutr 81, 16 (2005).
[3] Farschi, H.R., Taylor, M.A., Macdonald, I.A. Decreased Thermic Effect of Food after an Irregular Compared with Regular Meal Pattern in Healthy Lean Women. Int J Obes, 28, 653 (2004).
[4] St-Onge, M-P, Ard, J., et al. Meal Timing and Frequency: Implications for Cardiovascular Disease Prevention. Circulation 135, e96 (2017).
[5] Schoenfeld, B.J., Aragon, A.A.; Krieger, J.W. Effects of Meal Frequency on Weight Loss and Body Composition: A Meta-analysis. Nutrition Reviews 73, 69, (2015).
[6] Shaw, E., Leung, G.K.W, at al. The Impact of Time of Day on Energy Expenditure: Implication for Long Term Energy Balance. Nutrients 11, 2383 (2009).
[7] Takahashi, M.; Ozaki, M., et al. Effects of Meal Timing on Postprandial Glucose Metabolism and Blood Metabolites in Healthy Adults. Nutrients 10, 1763 (2018).
[8] Xiao, Q., Garaulet, M., Scheer, F.A.J.L., Meal Timing and Obesity: Interactions with Macronutrient Intake and Chronotype. Int J Obes 43, 1701 (2019).
[9] Aqeel, M., Forster, A., et al. The Effect of Timing of Exercise and Eating on Postprandial Response in Adults: A systematic review. Nutrients 12, 221 (2000).
[10] Hedland, M.L., Clifton, P.M., Keogh, J.B., Impact of Intermittent vs. Continuous Energy Restriction on Weight and Cardiometabolic Factors: a 12 Month Follow Up. Int J Obes – in press, 2020.
[11] Rynders, C.A., Thomas, E.A., et al. Effectiveness of Intermittent Fasting and Time-restricted Feeding Compared to Continuous Energy Restriction for Weight Loss. Nutrients 11, 2442 (2019).