5 Facts About Metabolism that are Misunderstood
We think we know a lot about weight management and our metabolism. But there’s a surprising number of misconceptions about both — and that can make it harder for us to stay healthy as we age. Here are five misunderstood facts about your metabolism.
What is Metabolism & How Does it Work?
Here are five misunderstood facts about your metabolism.
- Your metabolism slows as you age.
But only up until age 20 and then after age 60. New research published in 2021 suggests that, in fact, our metabolism stays consistent from age 20 to 60. What’s not true: Our metabolism peaks in our 20s and declines consistently afterward.
- Your metabolism will adjust to calorie restriction.
Initially, you may lose weight by cutting calories, but eventually your metabolism will adjust making losing more weight harder. This is called metabolic adaptation. As you lose weight, your body will need to burn fewer calories to maintain your weight, resulting in a lower resting metabolic rate. Your metabolism may also slow itself as a natural way to protect against starvation.
In a study of contestants on the television show "The Biggest Loser,” researchers found that resting metabolic rate decreased as contestants lost weight. Even as they regained lost weight or maintained their weight loss, their RMR did not return to their pre-weight loss rate.
- Women and men have similar metabolisms.
Women are different physiologically than men and generally have less muscle mass and lower basal metabolic rates, a measurement of metabolism. But when muscle mass is taken out of the equation, women and men have very similar metabolisms, according to researcher and author Herman Pontzer.
- Eating certain foods can speed up your metabolism.
This is true, but only to a point. Coffee, tea and some spicy foods seem to speed up your metabolism. Foods rich in protein may take more energy to digest. Ginger and cocoa have demonstrated remarkable metabolic benefits in mice. And other foods may even stimulate the expression of fat burning genes or give you a feeling of fullness that relieves hunger.
But the impact of these foods on your metabolism is negligible and won’t offset other poor diet choices – even if they do slightly boost your metabolism.
- Poor sleep can impact your metabolism negatively.
Two of the hormones that affect what we eat and how much – leptin and ghrelin – are impacted by our sleep patterns. Leptin tells us we’re full and ghrelin tells us we’re hungry. Unfortunately, when we miss sleep, we decrease our level of leptin and increase our level of ghrelin, which impacts our carefully balanced metabolism.