When we look to achieve weight loss, more often than not we will calorie count. But are the ratio of macronutrients as, or possibly even more, important?
Macronutrients are the three basic components of nutrition. Carbohydrate (CHOs), Protein and Fat, containing 4kcal, 4kcal and 9kcal per 1 gram of each. Water can be considered a fourth macronutrient, so then micronutrients include vitamins and minerals.
Weight loss at its simplest requires our bodies to be in an energy deficit for a prolonged period of time. To be in an energy deficit we have to look at our energy intake and energy output. Energy intake consists of the food and drink we consume, most notably the macronutrients. Energy output is made up of our resting energy expenditure, physical activity and the thermic effect of food.
If we consider there is 3,500kcal in 1lb of fat, we would want to tip the energy intake/output scale to a deficit of around 500kcal per day to lose a pound per week. Now here is the part where calorie counting becomes difficult, as how can we accurately calculate the balance of calories? Apps like myfitnesspal help us greatly in finding the total calorie values in packet foods, but what about home-cooked meals, are we going to weigh out every single ingredient to find an exact calorie value? Probably not.
On the other side of the scale can we estimate accurately the number of calories we burn from physical activity? Research has shown fitbits have a tendency to overestimate energy expenditure (Montes, 2017), so again probably not. Perhaps it doesn't matter if we are a little under or over here and there... Well, if an 80kg man was looking to maintain his weight by balancing calories over the next 10 years, he would gain 20lbs over these 10 years with an overestimation of just 20kcal per day. 20 kcal is the equivalent of one bite of a banana!
Why can utilising macros (particularly protein) help more?
If we look at a strategic weight loss plan with a 40%/30%/30% (CHOs, fats and protein) ratio, the main challenge here will be obtaining a protein content of 30% and limiting carbs to 40%, as the typical individual will consume 50-65% CHOs and less than 20% protein!
Out of the 3 macronutrients protein has the greatest satiety, with an increased elevation in satiety hormones after high protein meals and a greater perceived fullness. Protein also has the greatest thermic effect of the macronutrients, around 20-30% of proteins useable energy is expended for metabolism/storage, while CHOs only use 5-10% (Aaragon,2017). Therefore, higher protein consumption can help to preserve resting energy expenditure with weight loss. Higher protein will also maintain, and in some instances increase, lean mass in hypocaloric conditions (again helping maintain resting energy expenditure). By maintaining resting energy expenditure we can limit the plateau that often occurs with weight loss.
Some believe you should disregard total calories completely and purely look at the macronutrients, for instance if you were following a 40%/30%/30% (CHOs, fats, protein) plan hitting this would to some extent curtail your calorie intake.
In conclusion both are important, and yes I think we should definitely have an idea of the total kcal of the substances we consume, but we should also place larger emphasis on the macronutrient ratios, particularly protein, with a percentage of 30-35 of the total macronutrients most likely being optimal for weight loss!
- Stuart Ferguson
Montes J., Young C.J., Tandy, R., & Navalta J (2017). Fitbit Flex: Energy Expenditure and Step Count Evaluation. Journal of Exercise Physiology, Volume 20 (5).
Aragon A., Schoenfeld B., Wildman R., Kleiner., & Taylor L (2017). International society of sports nutrition position stand: diets and body composition. Journal of the international society of sports nutrition, Volume 14 (16).
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