With Atkins, Vegan and other radical diets being all the rage these days, I’m not surprised people are complaining about sluggish metabolisms (“I can’t lose weight…”), endocrine dysfunction (“I can’t sleep”, “I can’t get it up“) and chronic fatigue. There’s only so much punishment the body is willing to take.
What are the signs of a low metabolism? Is there anything you can do to speed it up? What type of training is best for metabolic health? Are carbs bad for you? Will Trump make the presidency? First things first. In this article I will show you how to boost your metabolism with the ease of turning up a car stereo.
Signs of a low metabolism:
- Impaired muscle growth and recovery
- Inability to lose weight/ keep it off
- Impaired cognitive function: thinking, speaking, memorizing
- Low energy and irritability
- Lowered body temperature (cold hands and feet)
The thyroid gland, situated below your Adam’s apple, is your metabolic gas pedal. If your thyroid is happy, your metabolism will be running at peak capacity. You’ve likely heard or read somewhere that thyroid insufficiency (hypothyroidism) is very common today and that there’s little you can do about it. But luckily, that’s not quite the case. Low thyroid function is not a disease or genetic trait. It’s an indication that your system is not performing up to standard.
Calorie Restriction and Your Metabolism
9 out of 10 people complaining about a weak or slow metabolism are either a.) eating too little or b.) too much of the wrong food. Prolonged dieting can chokehold your metabolism just as eating a shitty diet will.
In one of the most widely documented dieting experiments to date, healthy men receiving 50% of their daily energy requirements (approx. 1500 calories – half of what they’d need to sustain themselves) for 24 weeks, experienced a significant drop in metabolic rate.
A 50% energy deficit? Crazy, right? Absolutely. But it’s not uncommon in the world of detox cleanses and starvation diets. Before you eliminate carbs from your diet or jump on that juice cleanse remember that severe calorie restriction can suppress your metabolism for up to 6 years.
Calorie restriction and weight-loss will inevitably slow your metabolism down to some degree. Not a bad thing per se as eating less is associated with longer lifespans and lower rates of metabolic disease. Chronic food restriction, however, will make you a sad, depressed little puppy.
Keep your deficit to 20-25% of maintenance calories and refrain from doing massive amounts of exercise.
The Cardio Bunny’s Dilemma
Physical exercise is good for you. You knew that. But most people’s idea of exercise is reduced to some form of low intensity steady state cardio like jogging, cycling, or the newest cardio machine at the local gym. Problem is, excessive amounts of cardio will lower metabolic rate, increase stress hormone production and result in the dreaded skinny fat physique.
You’re essentially conditioning your body to survive on less fuel and get rid of “wasteful” tissue. This is the worst case scenario for a health conscious individual. You want more muscle on your frame and less time spent on a treadmill to nowhere.
Muscle is the most metabolically active tissue in the human body. It requires more fuel (calories) to maintain output and thus upregulates your metabolic engine.
Incorporate some form of strength training into your weekly routine. 2-3 sessions is all you need to jumpstart your metabolism and redesign your body. Low intensity cardio can never replace a solid resistance training routine.
“The energy cost of physical activity is proportional to body weight.” (Redman et al, 2009)
Overweight people have a higher metabolism than their lean peers. Eating an abundance of food increases energy expenditure and metabolic rate. This isn’t always a good thing as evidenced by obese populations. Chronic overeating comes at a cost and will eventually lead the way to degenerative disease (the story of western society).
The ultimate goal is not to have a fast metabolism. The goal is to have a healthy, functional metabolism that hums as smoothly as a high performance V8 engine.
“How do I boost my metabolism without getting fat?”
Eat Your Spaghetti
If you’ve been around the block a couple times, you’ve likely heard of leptin and its impact on metabolic function. Leptin is a satiety regulating hormone that drops during times of low food availability (i.e. weight-loss). While a slight dip is fine, you don’t want chronically suppressed levels, as they will interfere with hormone balance and metabolic rate.
Strategic overeating may counteract this natural tendency and keep your body firing from all cylinders throughout your diet. Take a day off from dieting every once in a while. Eat as much as you want (within reason) and refill the empty energy stores.
The leaner you get, the more often you’ll have to incorporate higher calorie days to keep your metabolic rate up.
“But won’t I get fat eating like that?”
In this study by Sagayama et al (2014) subjects eating a 1500 calorie surplus (that’s 1500 on top of maintenance calorie intake!) for 3 days in a row didn’t gain any fat-mass.
Short-term overfeeding is met with an increase in sympathetic nervous system activity and energy expenditure (Schutz, 1984/ Tappy, 1996). More energy coming in, more energy going out. This is the metabolic boost you want.
Out of all macronutrients, carbohydrates have the most profound impact on metabolic rate. If you chronically restrict your carb intake in an attempt to lose weight your thyroid output will nosedive (your thyroid hates low carb dieting). The other side of the spectrum is no better. For most people, I don’t recommend eating a high carb diet. Instead of trying to be part of a particular diet camp (high carb vs. low carb), adopt a more moderate approach to eating in general. Eat fats, carbs and proteins in the right amounts for you. Extreme diets are destined to fail.
“Refeeds” are a very common practice in the fitness and dieting world with the goal of maintaining metabolic rate during energy restriction. Due to leptin’s affinity for carbohydrates, most refeeding strategies are carb heavy affairs, with fats kept low to avoid weight gain.
There’s no need to stuff yourself with rice cakes and fat-free ice cream to make this work, however. I’d rather see you eat precisely the foods you crave on these select days of overeating. High carb, low fat refeeds never worked for me. At the end of the day, you want to intermittently maintain a positive energy balance, and thus give your body a break from dieting. Make it a weekly cheat meal, or even a cheat day if you’re already lean.
Am I giving you permission to eat whatever you like in the amounts you like? It depends. Read this.
“Isn’t there anything I can take to boost my metabolism?”
Despite the market exploding with products that claim to boost your metabolism and melt the stubborn fat off your body, there are no supplements, potions or “hacks” that’ll stoke your metabolism side-effect free. In case you’ve done everything detailed above and still feel like you’re underperforming, consider supplementing your diet with the following nutrients, preferably in the form of whole food.
Zinc, selenium and iodine have a profound impact on thyroid status and metabolic rate. Your thyroid needs sufficient iodine and selenium to convert the thyroid hormone T4 into the metabolically active T3.
Low zinc status is also associated with hypothyroidism. Make sure to get adequate amounts of these 3 powerhouses in your diet by eating fish and shellfish, using iodized salt and perhaps getting additional iodine from sea weed (i.e. kelp). Beef and oysters are great sources of zinc. Brazil nuts are valued for their extraordinary selenium content (and exquisite taste). If you don’t enjoy eating these foods consider supplementation.
Tread carefully though. An increase in metabolic rate calls for more fuel (= calories) to cover the additional output. If you “artificially” ramp up your metabolism but fail to provide sufficient energy, you will crash.
Your body is a highly adaptive organism. Don’t fool yourself thinking you can short-circuit biological principles that have kept us alive over millennia. The tools to a fast metabolism are your fork and knife, and a pair of dumbbells, not some diet elixir from the tropics.
How to ignite your metabolism:
- Eat more – No severe deficit, no macro restriction, high nutrient density, regular refeeds/ cheat meals
- Build some damn muscle
- Lower systemic inflammation – Food selection, lifestyle
- Emphasize thyroid supporting foods in your diet
Thank you for reading
Keys A, Brozek J, Henschel A, Mickelson O, Taylor H. The Biology of Human Starvation. Minneapolis, MN: University of Minnesota Press; 1950.
Leibel RL, Rosenbaum M, Hirsch J. Changes in energy expenditure resulting from altered body weight. N Engl J Med.1995;332:621–628.
Rosenbaum M, Hirsch J, Gallagher D, Leibel RL. Long-term persistence to adaptive thermogenesis in subjects who have maintained a reduced body weight. Am J Clin Nutr In Press; 2008.
Redman, L. M., Heilbronn, L. K., Martin, C. K., de Jonge, L., Williamson, D. A., Delany, J. P.(2009). Metabolic and Behavioral Compensations in Response to Caloric Restriction: Implications for the Maintenance of Weight Loss. PLoS ONE, 4(2), e4377
Sagayama, Hiroyuki, et al. Measurement of body composition in response to a short period of overfeeding. Journal of physiological anthropology 33.1 (2014): 29.
Schutz, Y., K. J. Acheson, and E. Jequier. Twenty-four-hour energy expenditure and thermogenesis: response to progressive carbohydrate overfeeding in man. International journal of obesity 9 (1984): 111-114.
Tappy, L. Thermic effect of food and sympathetic nervous system activity in humans. Reproduction Nutrition Development 36.4 (1996): 391-397.