Science Says: Quit Fretting Over How Often You Eat

Is it better to eat three big meals a day or numerous smaller meals for optimal climbing performance?


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Marisa Michael, MSc, RDN, CSSD is a board-certified specialist in sports dietetics and author of Nutrition for Climbers: Fuel for the Send. She serves on the USA Climbing medical committee and has a private practice in Portland, Oregon. Find her online at nutritionforclimbers.com or on Instagram @realnutritiondietitian.

True or false: Eating small, frequent meals will increase your metabolism.

False!

Although you may have heard of all sorts of “metabolism hacks,” the science isn’t so clear-cut. Should you eat three bigger meals, or smaller meals and snacks? Which is better?

Since we’re all climbers here, we’ll focus our question of meal frequency implications for climbing performance. Several research studies have explored whether three meals or frequent smaller meals is better for body composition, and there are mixed results. Research is riddled with inconsistent study designs, small sample sizes, short study durations, and different outcomes measured.

Some studies show that increasing the number of times you eat in a day is inversely correlated with body fat mass. This means that the more often you eat, the less body fat you may have. However, other studies have not shown the same results (correlation is not causation!).

And when we’re thinking about climbing, it’s not all about body composition. Skill level, flexibility, strength, endurance, and experience all matter much more than weight or body composition. Two reviews on this subject reveal that researchers estimate that measurable body characteristics such as weight, fat mass, and body mass index only account for 1.8-4% of total climbing ability.

So, the evidence doesn’t really support manipulating body weight or fat to improve climbing performance, especially if you are already at an appropriate weight. Which means you don’t need to overthink meal frequency, either.

Aside from body composition, climbing performance can also be influenced by adequate fueling. Eating enough to fuel climbing and recovery can go a long way. That could mean eating three meals, or smaller frequent meals/snacks, or even three larger meals and three snacks, depending on your individual needs and training load.

Eating bigger meals may help some people feel satisfied and fuller than small meals and snacks. This could be helpful if you have a busy schedule and can’t eat often, or just enjoy feeling full and fueled without hunger cropping up throughout the day. Score one for team “three meals.”

Here is what an all-day climbing meal pattern could look like:

Climbing Time Food Eaten
Breakfast 8 am Steel cut oats with walnuts, berries, and milk. Orange juice
Warm up 9 am Nothing unless hungry
Attempt 1 10 am Pretzels and sports drink
Fine-tuning beta 12 pm Lunch break Peanut butter and jam sandwich on white bread with apple slices. Chocolate milk
Another burn 3 pm Sports gummies or sports drink.
Try again 5 pm Raisins and sports drink
Send it at last! 7 pm Celebratory dinner that doubles as a recovery meal Quinoa bowl with black beans, salsa, cheese, avocado, and ground beef with a fruit and yogurt smoothie

~Adapted from Michael et al. (2019) Physiological demands and nutritional considerations for Olympic-style competitive rock climbing, Cogent Medicine, 6:1

However, three meals may leave you feeling uncomfortably full, sluggish, or bloated if you are actively climbing after said meal. Time your meals to fuel the climbing session, but not bog it down. You don’t want to be digesting the burrito while trying to send.

Low energy availability, the underpinning mechanism behind relative energy deficiency in sport (RED-S), is a concern for any climber. This refers to the body not having enough energy (via calories from food) to support body systems and exercise output. It’s crucial to get enough food to support all your body processes in addition to your training. Emerging data suggest that going without adequate energy—as small as a 300-400 calorie deficit—for even pockets of time within one day can lead to menstrual disturbances. One point for team “eat frequently.”

Among what researchers call “restrained eaters,” (basically dieters or disordered eating) females have decreased bone density and increased menstrual disturbances. This makes the case for eating enough. Another point for team “eat frequently.”

Amid the conflicting science, it’s safe to say that either meal pattern is probably just fine. A review of meal frequency (Schoenfeld et al, 2015, Effects of meal frequency on weight loss and body composition: a meta-analysis; Nutrition Reviews, 73(2):69-82) suggests that individual preference may take priority over nitpicking whether three meals versus six meals matters for any meaningful physiological outcome.

Eat what makes sense for you. Base meal timing and frequency according to your schedule, food preferences, hunger/fullness level, and meal satisfaction. Eating enough food and the right balance of macronutrients trumps meal frequency for climbing performance.