MARIKA SBOROS: Ripped actor Crews is a poster man for fasting intermittently before exercise
Fasting and fat-burning exercises have become a big trend in physical fitness circles, writes Marika Sboros
If it is good enough for hunky US actor Terry Crews, it is good enough for anyone. He believes the best food to eat before exercising is no food at all. He is a fan of intermittent fasting that has become a big trend in physical fitness circles.
He is also the best advertisement for what he preaches. Crews is a former National Football League player and host of Netflix’s TV series the Ultimate Beastmaster. In it, he leads elite athletes over an intense obstacle course competition. It is not for the faint-hearted. Neither is the diet Crews follows to stay in the best shape yet.
Now in his 40s, Crews has said he looks and feels better than when he was 22. He credits the right diet and intermittent fasting.
Crews works out very early every morning and according to reports, always skips breakfast. His first meal is at 2pm, his last at 10pm — he fasts daily for 16 hours.
It is not strictly true to say that Crews fasts, if that is according to the strict definition of abstaining from all food and drink. He reportedly sometimes has amino acids drinks. He is also not above a caffeine hit or two with coffee or tea. And he sometimes licks a little coconut oil off a spoon — it "makes you feel a little satiated but it’s never a meal", he says.
He has got that right. Coconut oil is mostly saturated fat and fat is extremely satiating.
But is this regimen really something to follow?
Crews has explained the logic behind his fuelling system in videos available on YouTube. He says it has to do with the biological concept of "autophagy". That is when the body almost literally "eats itself". "Autophagy" comes from the Greek word "autóphagos" and means "self-devouring".
Autophagy is not the same thing as auto-cannibalism. It is the scientific term for a benign process in which the body’s cells rebuild themselves. And in its infinite wisdom, it only does that when it goes without food.
The smart body first digests the food it is given, then gets to work repairing and rebuilding cells. However, there is no one-size-fits-all diet, or eating regimen before, during and after exercise.
Johannesburg dietitian Melanie Sher says intermittent fasting is a popular trend in SA. She has a special interest in sports nutrition — and much else besides.
Other interests include food allergies and intolerances, vegetarian and vegan diets and weight loss and management.
She explains that if there were any glucose around, the body will use that first as an energy source. Only when there is no recent supply of glucose — as happens in the fasted state, on an empty stomach — does the body use fat as an energy source. It goes into what is called the "fat-burning zone".
Sher says fat is a more efficient source of energy than other sources. It yields better output per gram than any other kind of fuel. Fat contains nine calories per gram compared with four calories per gram of protein and carbohydrate.
However, fat metabolism is a much slower process than with other macronutrients, Sher says. That is why the fat is predominantly used at lower speeds or intensities.
There is another factor to remember. When carbohydrates are taken in before training, you send "signals to your brain to switch to carbohydrate-metabolising pathways". Thus, it takes discipline and training over weeks to make fat-burning pathways more efficient.
And of course, there is always biological individuality. However, if not eating before exercising works for you, Sher supports it. That is as long as her two rules are observed: drink lots of water; and eat a good meal after training to replenish the body’s nutrient stores and rebuild tissues. Sher says intermittent fasting is a dieting pattern rather than a diet. "In simpler terms, it’s making a conscious decision to skip certain meals," she says. Intermittent fasting means eating calories during a specific "window of the day". Rather than focusing on what foods to eat, it focuses on when to eat.
Some people, Crews among them, choose to do this by skipping breakfast. That gives a 16-hour daily fast. Other methods include the "5:2" — five days eating followed by two days fasting.
Award-winning UK TV presenter and journalist Michael Mosley is credited with launching the 5:2 diet "revolution" in the UK and globally. Mosley is a medical doctor and author of The Fast Diet in 2012.
Since the publication of his book, more studies have shown the benefits of intermittent fasting not just for weight loss. It triggers changes within the body that reduce the risk of a range of diseases. In a Q&A on his website, Mosley says there is good evidence people who exercise in the fasted state burn more fat. Exercise can also be a "useful distraction" when "feeling peckish", he says. Mosley also cautions against trying to do a lot of endurance training on a fasting day.
That probably applies only to those on lengthy fasts, not the short, sharp versions that Crews is talking about here. I do know people who have remarkable energy and inclination to keep moving during extended fasting.
Controversy continues to swirl around carbs or fats as the best energy source. Sher says there is no consensus. She favours the "balanced" approach. Rather than focusing on percentage of carbohydrates and fat, Sher advises clients to consider quality as well amount of fat and carbohydrate they eat.
Extreme, restrictive diets are difficult to maintain long term, Sher says. Athletes and more ordinary mortals should create sustainable, healthy eating patterns. And enjoy workouts. That way they are likely to sustain an exercise regimen.
• Sboros is publisher and editor of Foodmed.net