Athletes in hard training should think beyond “calories in, calories out.”
by Pip Taylor
With resolutions in the rear view mirror and the race season fast approaching (or in full swing in the southern hemisphere), achieving the ideal “racing weight” is at the front of many athletes’ minds. But, before you start logging calories, there are some other factors to consider.
Counting calories is neither easy nor precise. Yes, you can make estimates of how much you ate and how many calories you’ve burned, but they are always going to be rough estimates. Errors in measuring foods and calories consumed are complicated by the fact that even caloric databases are only estimates. It has recently been shown that almonds provide approximately 30 percent less energy than previously stated, while some packaged meals contain significantly more (in addition to errors, 20 percent variance is allowed by law). Moreover, the more refined a food, the less fiber it contains, and the more readily calories are made available for absorption. (Refining essentially breaks down food. For example, flour versus whole grains.) Caloric databases do not always make these distinctions; calorie counting can yield some pretty unreliable results.
But things wouldn’t be much simpler even if we could accurately count calories. Other factors come into play, such as nutrient quality, our resting metabolic rate, how efficiently we use or store calories, our hormonal response to diet, exercise, stress and sleep and even our gut bacteria. Let’s take a look at how some of these complicate calorie counting.
Food: Microbes matter
Research shows that calories from plant based foods such as leafy greens, vegetables, fruits, nuts and seeds are associated with weight loss, whereas the same number of calories consumed from potato chips or burgers resulted in weight gain. In addition, whole foods optimize gut bacteria, which are gaining recognition for its role in body weight and composition. Not only does what we eat influence the bacteria in our gut, but this microbial population also determines how much energy we’re able to extract from our food. Research shows that bacteria from obese people are very different from lean ones and that overweight subjects gleaned more calories from their food than the lean ones. To keep your gut happy, feed it a healthy diet of probiotics (fermented foods like yogurt, miso and kefir, and prebiotics (fibrous plant foods), while minimizing processed and refined foods.)
Lifestyle: Hormones, stress and sleep
Hormones play a key role in determining body weight and composition. Foods high in sugars and refined carbs cause the hormone insulin to rise, whose very job it is to reduce the resulting high levels of blood glucose. Glucose is used directly by the brain and muscles for energy, but excess glucose is converted and stored as fat. A high level of insulin increases the storage of fat and prevents the body from being able to use stored fat for energy use. To control insulin spikes and the way your body responds to it, cut back on sugary and refined foods. Proteins and fats do not cause the same insulin response and are more satiating.
Related Article: Why Sleep Matters for Triathlon
Reducing stress and getting adequate sleep are also essential factors in the weight game. Fewer hours of sleep causes a decrease in leptin, the very hormone that decreases appetite, and an increase in ghrelin, a hormone that stimulates appetite. Cortisol, the hormone that also increases with stress, is also known to increase appetite and cravings for sugary and fatty foods. Research subjects who were sleep deprived and had high levels of stress also had higher levels of body fat. Cortisol is also part of the reason that cutting calories drastically can backfire—when calories are in too limited a supply, cortisol goes up. This is especially true for athletes under high physical workloads.
In short, calories do matter, but when it comes to body composition and pounds gained and lost, “calories in versus calories out” is too simple a maxim. Cultivate awareness for these factors, while keeping an eye on what and how much you are eating. But leave the number crunching for math class.
Pip Taylor is a professional triathlete and nutritionist. Visit her website