Note: This is an article I wrote as part of a job application (didn’t get the gig). I spent a butt-load of time looking up research for it, so I felt it would be a waste if it never saw the light of day. Even though it’s, you know, A REJECT.
When the scale won’t budge it’s easy to chalk it up to a slow metabolism. What about that guy who lives off doughnuts and never seems to gain a pound? He must have a fast metabolism, right? Well, not exactly. The answer is a little complicated, but the good news is that being overweight doesn’t have to be a life sentence.
Why It Matters
Metabolism is the set of chemical reactions that happen in our body to convert food into energy. This process helps to fuel all of the functions we need to live, from breathing to keeping our heart beating. Another way of thinking of metabolism is total daily energy expenditure (TDEE), which accounts for all the calories we burn in a day.
Lots of things can influence TDEE, like body composition (how much fat and muscle a person has), age, activity, and how much someone eats. The more muscle someone has, the more calories they require to maintain that muscle. Younger people also tend to have higher metabolisms.
Based on these factors, everyone has a unique TDEE, and thus, a unique calorie requirement. While our metabolisms are special snowflakes with their own individual energy needs, the number of calories we burn is still largely dependent on our diet and activity levels. In most cases, excess weight is due to eating too much and/or moving too little. Slow metabolisms are rare and usually not the cause of obesity.
“I don’t really believe in ‘fast’ or ‘slow’ metabolism. It’s much more complicated than that,” says Krista Scott-Dixon, PhD, research director for the Healthy Food Bank and creator of women’s weightlifting site, stumptuous.com. “In fact, if your bodyweight is higher, you are just as likely to have a “fast” metabolism — because you probably have more lean body mass (including bone density) to carry a larger body around, and your body has to make a larger system function properly.”
You’re the Boss — The Answer/The debate
There are situations where hard work doesn’t pay off. When people have hormonal issues such as hypothyroidism or Cushing syndrome it’s much more difficult to lose weight. There are also certain genes that predispose folks to be overweight or obese.
The good news is that thyroid disorders can be treated and genes only play small role in determining weight. Ultimately, we do have control over our body size, even those who have a genetic predisposition to be heavy.
To lose weight, one must burn more calories than they take in, either through reducing the amount they eat, exercising more, or a combination of the two. It’s the good ol’ calories in vs. calories out model. There are also certain methods that increase metabolism. But for the most part, eating healthy and being active are the best choices for staying trim.
- Metabolic Effect — Is Your Metabolism Broken?
- Time — Can Exercise Trump Genetics?
- Precision Nutrition — Genes vs. Workout Program
- Mayo Clinic: Metabolism And Weight-loss: How You Burn Calories
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8. Who does not gain weight? Prevalence and predictors of weight maintenance in young women. Ball, K., Brown, W., Crawford, D. Centre for Physical Activity and Nutrition Research, Deakin University, Melbourne, Australia. International journal of obesity, 2002;26(12):1570-78.