Diet and exercise runs hand in hand, we’re so often told, but is the truth so simple? Can you do one without the other and still achieve results? Jon Sutton has a look.
The relationship between diet and exercise has never run smoothly. It can be nigh-on impossible to get excited over the benefits of kettlebells and kale when you’re being stalked around the clock by the dastardly duo of cake and couch. But which of these metrics holds the key to long term weight loss: diet or exercise?
In a recent study, 90% of weight-losers reported one hour per day of light-to-moderate exercise – but that study only served to cloud the issue, since it’s difficult to know whether the weight loss was actually down to diet or exercise or a combination of both. For many years, literature has hovered around the 80/20 rule, which suggests that 80% of weight loss should come through diet and 20% through exercise. But today’s experts are a little more divided on the facts.
Michele Olson, PhD, in defence of exercise, told Huffpost: “Exercise is an important component. Without it, only a portion of your weight loss is from fat – you’re also stripping away muscle and bone density. Since working out stimulates growth of those metabolic tissues, losing weight through exercise means you’re burning mostly fat.”
Shawn M. Talbott, giving the case for the opposition, countered: “As a rule of thumb, weight loss is generally 75% diet and 25% exercise. An analysis of more than 700 weight loss studies found that people see the biggest short-term results when they eat smart.”
Giving a more detailed view, Dr Emily B Porter MD, in one of her highly informative YouTube videos, has this to say on the topic: “I’d encourage people to start with diet. It’s much easier to cut calories from diet than to burn them through exercise.” This would perhaps suggest that diet is the best starting point for weight loss or getting healthier and that exercise should come next. Dr Porter goes on to explain the potential issues of exercising whilst trying to lose weight: put simply, “the more you exercise the hungrier you are going to be.” This will likely lead to eating more and the pattern could continue into weight gain.
But Dr Porter does offer viewers advice on how to curb weight gain by keeping a diary and identifying – then addressing – areas of indulgence in processed or sugary foods. Whilst that advice may cover what to eat, another aspect of the argument leaving experts divided is when to eat: before or after exercise? For many years, we’ve been sold the benefits of the pre-workout snack as a way to boost energy levels and guarantee peak performance in the gym, but studies now show that it actually may be more beneficial to train on an empty stomach.
The University Of Bath, in a recent study, proved that exercising whilst fasted will ensure that you burn body fat instead of food. Sounds straightforward enough in theory; if there’s no food in the belly, then there’s nothing to burn but body fat. Yet the truth is not quite so easy when considered outside the realms of this low-intensity study and into the world of high intensity workouts.
Experts believe that the human body can return better results when burning food-fuel than its own fat reserves. And it’s thought that the increased energy levels experienced after eating allow for a higher level of intensity to be achieved, leading to more calories being burned by the exerciser in the long term. Chris Carmichael of trainright.com says that, if you train on an empty stomach, “your power outputs during interval workouts will decline.” And fitness expert Laura Williams told Harper’s Bazaar: “Research has shown that training in a fasted state burns more fat during the workout, but training in a fed state leads to higher fat oxidation over a 24-hour period.”
As with most dietary and exercise advice it seems, the answer lies in trial and error. Find what works for you – and stick to it.