Does intermittent fasting actually work?

A Mediclinic dietician unpacks the benefits of intermittent fasting.

Intermittent fasting benefits

In recent years, intermittent fasting has grown increasingly popular for people keen to lose weight and lead a healthier life. While it may not be ideal for everyone, a dietitian can provide guidance on safe and effective approaches to weight management.

“Research has shown that, on a short-term basis, patients who fast intermittently can lose between three and eight percent of their body weight,” says Carmen Basson (Kruger), a dietitian based at Mediclinic Hoogland in Bethlehem. “Other research shows intermittent fasting can be beneficial to the hormones that regulate one’s appetite, especially leptin.”

Leptin – known as the appetite suppressor – is the hormone responsible for signalling to one’s brain that we are full, while ghrelin increases appetite.

Basson (Kruger) notes that people who are very overweight tend to have very high levels of leptin, which can cause a lack of sensitivity to the hormone, a condition known as leptin resistance. Intermittent fasting, while not suitable for everyone, can help balance out these hormonal levels. Research also indicates that intermittent fasting helps with glycaemic control for people with Type 2 diabetes.

Is intermittent fasting for you?

Intermittent fasting can take various forms. The basis of intermittent fasting is an eating window of a few hours each day, (usually eight hours) and then fasting for the next 16 hours. This generally means eating two meals a day – brunch and early dinner. Some people who fast intermittently prefer to eat for five days and fast for two.

“Intermittent fasting can be coupled with side effects, which may include a lack of energy, feeling cold, headaches, lack of concentration and constipation,” says Basson (Kruger). “Research has shown these side effects do reduce with time. A dietitian can test your fat and muscle composition as well as how much water your body retains to know what the best diet is for you.”

To make sure you are on a track to health, book an appointment with a dietitian who can guide you on the safest and most suitable ways to manage your weight with diet and exercise. Pairing intermittent fasting with the correct exercises will help to ensure that you burn fat and build muscle.

A healthy relationship to food

The dietitian notes, however, that research has also shown that when compared to a healthy diet that isn’t limited to an eating window, the results of intermittent fasting are similar.

“It is critical to look at what you are eating and the nutritional quality of that food. A balanced diet, not necessarily linked to an eating window, can be just as effective.”

Intermittent fasting may not be for everyone, says Basson (Kruger). “Your relationship to food should always be positive. For some people, having ‘eating windows’ and limiting the time for eating can lead to a negative relationship to food. If you are fasting intermittently, your meals should still be nutrient-dense.

Let a dietitian guide you

If you are considering trying intermittent fasting, it is important to work with a dietitian. they can guide you on the best way forward and ensure you eat a healthy, balanced diet.

“A dietitian will ensure that your diet meets your nutritional needs when it comes to proteins, carbohydrates, fats, vitamins and minerals, dietary fibre and water,” says Basson (Kruger).

She notes it is very important to be aware of diets that can trigger eating disorders. Hopping from one diet to the next can also increase your poor relationship with food.

“When you consume less energy (food), you create an energy deficit and your body burns up fat. But when you are not eating optimally during your eating window, your body may break down muscle instead. This can slow down your metabolism and make it more difficult for you to lose the right kind of weight. Not eating optimally can also reduce your stamina during exercise,” says Basson (Kruger).