We’ve always been told not to skip meals, and that even if we’re trying to cut down on our calorie intake, we should go for smaller portions and healthier options. However, some studies suggest that intermittent fasting may help with weight control, improve brain health and slow down the effects of ageing. Intrigued? Here’s the lowdown.
Popular types of intermittent fasting
Intermittent fasting involves periods of eating and fasting. And since it isn’t so much about the foods you should eat, but when you should eat them, some people don’t consider it diet a type of diet. But Bridget Marr, a dietitian at Nutritional Solutions, disagrees.
“I believe it’s a diet as it involves restrictions and changes to current eating habits,” she says.
There are several kinds of intermittent fasting regimes, but a well-known one is the LeanGains method, which involves fasting for 16 hours each day. Essentially, eating only takes places during the remaining eight-hour window.
The eating and fasting schedule should be consistent every day, and people who follow this method typically only consume two meals between the hours of 1pm and 9pm. This timing is popular because it allows them to still enjoy lunches and dinners with friends.
Another common method is the Eat-Stop-Eat method, which involves fasting for 24 hours once or twice a week. It may sound tough but here’s the thing: after the 24 hours, you can go back to regular eating. There’s nothing you’re not supposed to eat, and no need to count calories.
It’s a simple math equation
Intermittent fasting methods usually involve fewer than three meals, so there is a reduction in calorie intake if you’re used to always having breakfast, lunch and dinner. This naturally leads to weight loss over time.
Some studies* have also suggested that it changes your metabolism at a genetic level, so you burn more calories even when doing nothing. And by helping you to eat less (fewer calories in) and burn more (more calories out), intermittent fasting is believed to promote weight loss by altering both sides of the calorie equation.
The are pros and cons
On top of helping you to lose weight, intermittent fasting can also boost your health in others ways.
“It has been shown to be effective at reducing the visceral fat around our internal organs. [Excessive visceral fat] contributes to metabolic syndrome and Type 2 Diabetes,” says Bridget.
Not convinced? A study conducted by researchers at the USC Leonard Davis School of Gerontology found that intermittent fasting can decrease the risk of cancer and heart disease, while another study by Harvard University also showed that it can even increase your lifespan.
However, dietitians are divided about the long term benefits of intermittent fasting. Many even discourage it altogether as a dieting strategy. One of the main reasons is it can lead to rebound overeating, where those who try but fail to restrict their eating hours consume a lot more than they normally would out of frustration.
It could also lead to a dip in sleep quality, with some reporting they have a hard time falling asleep and constantly wake up through the night when they’re on the diet. This in turn wreaks havoc on their daytime energy, and disrupt their hormone levels, making them feel hungry even when their bodies don’t need food.
It’s not recommended for everyone
Want to give intermittent fasting a go? You ought to consult a doctor first because it’s not for everyone.
“I recommend it in general, except for those with a history of eating disorders. They need to eat regularly and avoid restrictions as those restrictions can trigger the ‘eating disorder voice’ in their heads,” says Bridget.
It’s also unadvisable for those who struggle with obesity.
“For overweight individuals, the weight loss may help to reduce their risk of obesity-related chronic diseases. But without discipline and control, the weight gain during the maintenance phase can beeven higher [than before],”says Louis Yap, a dietitian at Parkway East Hospital.
As with all diets, speak to a medical professional before embarking on it.
*The American Journal of Physiology, January 1990; The American Journal of Clinical Nutrition, June 2000