Feast or famine – Could fasting be the path to sustainable weight loss and good health? The answer to this question will depend on whom you ask.


So what exactly is intermittent fasting? It is a dietary approach that restricts calorie containing food and drinks for at least 16 hrs. Intermittent fasting could also be when you eat normally on some days and little to nothing other days.

This ‘dietary approach’ has gained attention recently for its purposed weight-loss benefits. Advocates of this dietary approach believe that it is a good way to not only lose weight quickly but also to reduce risk factors for some diseases of lifestyle such as diabetes and heart disease. Those who are not so prone to this approach, see it as a poor choice, making sustained weight loss more difficult and the belief that it could be harmful to one’s health.

The History Of Fasting:

Humans have a history of fasting for many centuries and it has been for many various reasons – religious reasons or to express social and political views. Fasting as an approach to weight loss took off in 2012 after British journalists Michael Mosley and Mimi Spencer published their book the FastDiet.

Not all fasting diets are the same – it can be two days on and five days off or it could be 24-hour fasts one or two times per week, or randomly skipping meals in the week. You also get alternate-day fasting where you would fast every other day.

Proposed Reasoning For How And Why Fasting Works:

You eats less in one week than you normally would and anytime you consume fewer calories than you can burn, you should lose weight. There is also the proposal that alternate-day fasting can be easier for some people than reducing the number of calories they eat every day.

The key to intermittent fasting is to make sure that you do not overeat on “feed” days (these would be your normal eating days).

What Does The Research Show?

There is some evidence that intermittent fasting can cause weight loss and improve risk factors for heart disease, but many believe that “there are better diets that we have long-term evidence on”.

Currently there are too many unknowns, especially long term with intermittent fasting. It is definitely not a good diet for:

  • pregnant women
  • those with health conditions
  • those that need to take medication throughout the day.

Fasting can also make people feel dizzy, lightheaded, tired, and nauseated. Exercise may also be affected.

Intermittent fasting is not a healthy way to lose weight. Often the weight lost on this dietary approach is gained back more quickly once normal eating is resumed. This is due to your body being forced to “dip into its energy stores and that can mess with your metabolism”.

According to the American Dietetic Association “Animal studies and preliminary human studies indicate that this method might positively impact our health, possibly reducing risk factors related to diabetes, cancer and heart disease.” But they also state that “additional human studies are needed to determine any health benefits and especially comparing intermittent fasting to other calorie-restricted diets”.

The Bottom Line:

Currently there is not enough evidence to support advising intermittent fasting as a weight loss strategy. This approach is definitely not very everyone and won’t work for people who are used to eating small regular meals. It is also definitely not advised in pregnant women and those taking medication.

This diet doesn’t teach you about listening to your body cues and body hunger and there is the potential for people to over eat on their ‘normal eating days’ as they might feel like they ‘derserve it’.  This dietary approach also doesn’t teach you about making healthy food choices, which we are so passionate about at Munchwize.

If you would like to lose some weight, rather make an appointment to see a registered dietitian who can work out an individualized plan for you that is healthy, sustainable and teaches you about making good food choices.

Munchwize registered dietitians Cape Town are based in Claremont. To book an appointment, contact us here






Dubost, J. Intermittent fasting: A good approach? American dietetic association. 2014

Orenstein, B. Intermittent Fasting: The Key to Long-Term Weight Loss? Today’s Dietitian. Vol. 26 No. 12 P. 40