#1. Metabolism Myth: Skinny People Have a Higher Metabolic Rate
In reality, people who weigh more have higher energy requirements and a faster metabolism. When a person is carrying more weight they burn more calories at rest and when they’re moving around. That’s one reason it becomes harder to shed those last few pounds. Your energy requirements go down with your body weight. When you’re lighter, you’ll burn fewer calories running on the treadmill than an overweight person because you have less body mass to move through space.
What about people who seem to be naturally thin and can eat whatever they want? These people may be naturally more active or expend more energy through NEAT or non-exercise activity thermogenesis like fidgeting. They may also have more metabolically active brown fat that helps them release more energy as heat. Genetics are also a factor.
#2 Myth about Metabolism: You Can’t Change It
One of the most powerful ways to give your metabolism a boost is to exercise, but working out at a slow, steady pace isn’t the best way to do it. High-intensity interval exercise where you work out at a very vigorous pace for short periods of time and then recover boosts your metabolic rate for hours after you finish. That’s because your body needs more resources for repair and recovery after an intense workout. Think sprinting rather than jogging.
The other type of exercise that can boost metabolism is resistance training to build lean body mass. Muscle is more metabolically active than fat, so the more muscle you carry the greater your energy requirements will be. Each additional pound of muscle you carry burns more calories all day. That’s one reason men have a higher metabolic rate than women. They have more lean body mass.
#3 Metabolism Myth: Metabolism Slows Down with Age, and There’s Nothing You Can Do About It
Metabolism slows down a little each year after the age of 20, but much of this slowdown is due to inactivity and loss of lean body mass. Regular resistance training using heavy weights to build strength and muscle can offset much of this decline. Getting adequate sleep is important for priming your metabolism too. Lack of sleep contributes to insulin resistance, which reduces metabolism and leads to weight gain.
#4 Myth: You Can Dramatically Boost Your Metabolism by Eating Hot and Spicy Foods
Spicy foods that contain an ingredient called capsaicin found in hot chili peppers causes a temporary metabolic boost, but the effect is short-lived. Twenty minutes after singeing your mouth eating peppers, your metabolism will have returned to baseline. Eating hot peppers won’t have a sustained effect on your metabolism.
You can burn a few more calories with meals by eating more frequently and eating lean protein with every meal and snack. Every time you eat something your body has to expend energy to process and digest it. This is called the thermic effect of food. Digesting and processing protein expends more energy than breaking down carbohydrates and fats. Sipping green tea during the day may subtly boost your metabolism because of the caffeine and catechins it contains.
The Bottom Line?
If you feel like your metabolism is slow, ask your doctor to check your thyroid function and review your medications to make sure they’re not a problem. Some medications can slow down metabolism and increase appetite. Start tracking how much you’re eating by keeping a food journal. Then head to the gym on a regular basis to do high-intensity interval training and lift some weights.
Exercise Physiology. Fifth edition. 2001. McArdle, Katch and Katch.