Once upon a time, it was almost universally accepted that the lower the number on the bathroom scale, the better shape you were in. But according to the flawed logic of the body mass index (BMI), bodybuilders are “overweight”. And the Rock? “Clinically obese”.
Now that we know better, the BMI’s days are numbered, and body fat percentage has stepped up to the plate to tip the scales in your favour.
Tracking your fat-to-muscle ratio can do more than melt away the male muffin top: it’s a reliable marker of health. It doesn’t matter what the scales say – the more body fat you have, the greater your risk of heart disease, stroke, type 2 diabetes and death from all causes. If more than a quarter of your bodyweight is fat, you’re playing fast and loose with your health.
So, how lean can you get before turning translucent? The answer lies in your genes. “A healthy body fat percentage differs for all individuals,” says PT and transformation coach Mark Ross. “Some lean men will be healthy at a very low percentage, because they have a fast metabolism. But others won’t be.”
While the ballpark for a toned, lean physique is somewhere between 5-15 per cent, single-digit body fat is considered “stage lean”, says Ross. Fat is technically an organ, and your body needs a certain amount to function. Going below your natural level requires a food-as-fuel bodybuilder mentality. “It’s not achievable without 24/7 effort and full focus,” he says. No room for Deliveroo and work-night beers, then.
Without fat reserves, your immune system takes a battering, testosterone levels tank and your metabolism stutters. Dip below 5 per cent and you risk muscle loss, nervous system damage and brittle bones, at best. At worst, you leave the gym in an ambulance.
So, unless you’re a professional bodybuilder, maintaining a 10-14 per cent body fat percentage is the best way to balance good health and a lean, athletic physique.