Updated: Jul 22, 2020
The word metabolism is an everyday ‘go to’ word for people to use as an excuse for not losing weight or indeed not being able to gain weight. I’m sure you’ve heard someone say they can’t lose weight because they have a slow metabolism and whilst there is some truth in this, the difference between a naturally high and low metabolism is smaller than you’d think. Saying this, there are ways to increase your metabolism and also ways you can slow it down (those of you who have been trying to lose weight for a long time or have tried crash diets, you’ve probably experienced in inadvertently slowing down your metabolism).
Metabolism is the chemical process your body goes through to breakdown food to provide fuel for the body (primarily carbs), initiate protein synthesis / avoid protein or muscle breakdown (protein) and improve cell and brain health (primarily fats). A high metabolism means your body is very efficient at using food for these needs, which means you can afford to eat more without the negative effect of storing much as fat, alternatively a low metabolism means you’re not as efficient at using these foods for their purpose and therefore you can process less which means more is stored as fat. Example: a 90kg male with a higher metabolism can consume 3000kcals at maintenance (their bodyweight isn’t changing), another 90kg male with a lower metabolism can consume 2000kcals at maintenance. Let’s say both males want to lose weight, if you reduce both of their calorie intakes by 500kcals, one male is consuming 2500kcals and the other is consuming 1500kcals, and this is where the problem lies. Once our now 1500kcal male stops losing weight he doesn’t have as many calories to manipulate. It could be too risky to reduce his calories further as there will be a distinct lack of energy and micronutrients, so weight loss will plateau and because his maintenance calories is now at 1500kcals he is now at risk of gaining weight when he moves back up in calories. On the other hand the now 2500kcal male can still afford to reduce his calorie intake by 5-15% carbs and/or fats if he hits a plateau and will still be eating enough and have sufficient micronutrients for bodily functions and sufficient energy to perform exercise and his daily routine.
So what could our slow metabolism guy do about it? The answer is – before he reduces calories, he needs to increase them. Firstly going from experience the chances are that he’s not eating enough protein. Protein has a thermogenic effect meaning it burns up to 30% more calories whilst being digested compared to carbs, it also improves satiety, builds muscle and aids the disposal of glucose into the muscles when consumed with carbs. Second of all his total daily energy expenditure (TDEE) is very low because he’s been eating so little for so long, meaning as soon as he increases his calorie intake, his TDEE will increase and he’ll burn more calories. Furthermore it will improve his performance in the gym, and whilst this isn’t at the top of everyone’s agenda, it’s important to know that muscle is metabolic! Some studies have shown that 1lb of muscle has the potential to burn up to 50 calories extra every day so if he trains better and has the calories to build muscle, it will also help him lose body fat.
In effect, eating more of the right foods will help you burn more calories, move more, train better and improve your body composition if done correctly. This needs to be done gradually with a phased approach which is too long to explain in one post, but if you want to try a quick, simple trick, try doing 300kcals worth of cardio first thing in the morning or last thing in the evening (or just around the time of your weight sessions) and up your calories by 300kcals. If you do this everyday you’re giving yourself 2100kcals a week extra, being more active and improving cardiovascular health. If you have any further questions please email us at @@
Greenway. F. L., (2015). Physiological adaptations to weight loss and factors favouring weight regain. International Journal of Obesity.