Studies show poor physical fitness correlates strongly with mortality, particularly cardiovascular disease*. Fat people with good fitness have a much lower risk of death (overall mortality rate) than unfit, fat people. And thin people with poor fitness have a higher risk of death.
The bigger killer is not obesity – it’s inactivity.
Part of the reason we are led to believe obesity is the biggest culprit is the billion dollar diet industry. The diet industry is a scam. Following diets can see you lose kilos of weight, but most people gain it back within the next few years. Dieting can make you thinner, but it does not necessarily make you healthier. This is because dieting is not maintainable, and it doesn’t get you off the couch.
Exercise, on the other hand, makes you healthier. It is not a scam. Many people who take up exercise will stick with it. This is because it makes you feel good: you get stronger, more functionally fit, energetic, happier, cravings and appetite more controlled, improved sex drive, sleep and metabolism. The effects are both immediate and long term.
However, exercise alone will not make you much thinner. It lowers your risk of cardiovascular disease, but even a vigorous exerciser loses, on average, a couple of kilos of body weight. So what do you want?
If you want to temporarily lose weight, diet.
If you want to get healthier, exercise.
If you want to lose weight, keep it off, AND be healthy: you should exercise regularly, eat a clean, nutritious diet and achieve a marginal calorie deficit (for weight loss).
*Source: ‘Flourish: A new understanding of happiness and well-being’, Dr Martin Seligman, 2012