Carb Backloading: Why Breakfast Is Not the Most Important Meal of the Day

STACK Expert Mitch Calvert makes the case for carb backloading and ignoring the conventional wisdom about breakfast, with one exception—for endurance athletes.

beautiful breakfast

Breakfast, "the most important meal of the day." Nowadays this could be considered the most essential rule in nutrition. If you want to have energy to fuel your day and your workout, better get up and eat your oatmeal. (We've said it: Athletes Eat Oatmeal for Breakfast.)

Fuel with carbohydrates early in the morning and gradually reduce your intake throughout the day, adding quality fats instead. Fitness industry experts have been telling us this for years. But is it really the best plan for optimal performance? It certainly doesn't fit the biological clock our ancestors abided by.

Popular diet trends like John Keifer's "Carb Backloading" have challenged the conventional wisdom with documented results. (Read more on carb backloading.) Keifer says, "Limiting carbs in the first half of the day forces your metabolism to rely on fat for its energy needs. When you limit your intake of food during this time, your body releases body fat for energy."

It's not just about diet fads. A 2010 study reported in the International Journal of Obesity recommends a complete reversal of today's "carbs for breakfast" mindset. The study, entitled "Time-of-Day-Dependent Dietary Fat Consumption Influences Multiple Cardiometabolic Syndrome Parameters in Mice" [1], suggests that consuming a meal higher in fat early in the day helps the body respond more appropriately to carbohydrate later in the day, whereas a high carbohydrate morning meal fixes metabolism towards carbohydrate utilization, impairing the body's ability to adjust metabolism toward fat utilization.

The take home message: avoid insulin-spiking foods (carbs) in the early part of the day, especially if you work a sedentary desk job. Fill up on carbs at night or after exercise, when your body is primed to absorb them properly in muscle cells. A sample menu would include early meals of lean meats, eggs, fibrous veggies and low glycemic carbs like berries, and pasta for dinner. Logically it makes sense. Eating carbs increases the production of serotonin, which makes you sleepy, so the best time to eat them would be a few hours before bedtime.

A counter-argument states that if you work out early in the morning, you need carbs for fuel. But research suggests a carbohydrate load the night before should be sufficient to keep you energized through a weightlifting workout. A 2013 study, "Nutrient timing revisited: is there a post-exercise anabolic window?" by researchers Alan Aragon and Brad Schoenfeld [2], recommends consuming 0.4-0.5 g/kg of protein per kg of lean body mass both pre- and post-exercise to negate any potential performance shortfall. That said, they note that endurance athletes need to take in carbohydrate during and after exercise, in contrast to athletes pursuing strictly strength or hypertrophy goals. Essentially, if your morning exercise is a prolonged endurance activity (say a two-hour hockey practice bright and early), then carbohydrate intake prior, during and after is appropriate for optimal performance.

Whether you adopt the Keifer's method or modify it to suit your athletic needs, don't be afraid to try a new approach. You may find your reward from ditching the oats is improved performance. And what athlete doesn't want that?


[1] Bray et al., "Time-of-Day-Dependent Dietary Fat Consumption Influences Multiple Cardiometabolic Syndrome Parameters in Mice." International Journal of Obesity (London). 2010 November; 34(11): 1589-1598.

[2] Aragon, A. & Schoenfeld, B., "Nutrient timing revisited: is there a post-exercise anabolic window?" Journal of the International Society of Sports Nutrition. 2013 January,

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