OUR METABOLISM
that eating them in excess won’t help you lose weight.
Include protein-rich foods – lean meat, fish, poultry, eggs, tofu and Quorn, for example – at each meal. Studies show protein-rich foods cause a 20-30 per cent rise in metabolic rate compared with just a 5-10 per cent increase for carbs and less than three per cent for fat. One study found a high-protein, low-fat diet produced double the fat burning effects of a high-carb, low-fat diet. A study published this February compared a group of people eating wholegrains with a group who ate refined white grains. After six weeks, the researchers found those in the wholegrain group passed more stools with a higher calorie content and had a slightly higher BMR (basal metabolic rate) than those in the refined white grains group.
After adjusting for other factors, the average daily loss for the wholegrain group was 92 calories a day.
More studies are needed to confirm these findings and identify whether this is an effective way to boost our BMR. But we already know wholegrains provide good amounts of fibre (we should aim for 30g a day) and are associated with a number of other health benefits, including a reduced risk of bowel cancer. So choose brown rice or pasta, wholemeal bread, wholegrain cereals and oats – if they boost our metabolism, even better. It may not be what we eat but how we eat it that has an impact on how many calories we burn.
In one study, adults who ate a meal over 10 minutes burned 30 calories. When they ate the identical meal on a separate day over 40 minutes they burned 81 calories.
Slowing down also gives the brain the time it needs to receive the ‘I’m full’ message from the stomach and helps to keep us fuller for longer, which reduces the amount we eat.
Eat each meal slowly and give it your full attention – that means no television, smartphones, computer screens or other distractions.
Take your time chewing and put your cutlery down between mouthfuls. Crash dieting and extreme calorie reductions slow metabolism as our body thinks food is in short supply and so responds by conserving energy – exactly the opposite to what we want to achieve when we’re trying to lose weight. In times of starvation (which is effectively what happens with a crash diet), the body starts to break down muscle as well as fat to provide it with the calories it needs to function. This is bad news for our metabolism because the less muscle we have, the slower our metabolic rate and the fewer calories we burn. Then, when we go back to eating normally, a slower metabolism means we don’t need as many calories as before, so we pile weight on more quickly.
Instead, follow a healthy eating plan which reduces calories slightly and exercise regularly to burn calories and strengthen muscle. The benefits of exercise are two-fold. First, aerobic activities such as running, cycling and brisk walking increase the amount of calories we burn. Plus, aerobic exercise can lead to the afterburn effect, where the body continues to burn calories faster for many hours.
Strength training also helps to build lean muscle. “Muscular activity is a very good way of burning calories and enhancing metabolic rate,” says Dr Barber. The more muscle we have, the higher our BMR.
Exercising regularly is even more important as we age. By the time we are in our 30s, our body starts to lose muscle – and the more inactive we are, the faster this happens.
The full version of this article appears in the May edition of Healthy Food Guide.