Intermittent Fasting: Weighing Up The Pros and Cons

Article by Jennifer Dawson — photo by Jannis Brandt


With over two-thirds of adults in North Carolina either overweight or obese, there is a real need for effective dieting programs here. Local initiatives, such as Eat Smart Move More, encourage weight loss through proven methods of healthy eating and exercise. But there’s a growing global trend in an alternative method of dieting: intermittent fasting (IF). It’s a cheap and easy way to reduce weight and has the by-product of an array of health benefits, from reducing the risk of life-threatening diseases to improving cognitive function. Fasting is indeed the new dieting!

So what exactly is IF?

In contrast to calorie-controlled diets that limit the intake of certain foods, IF diets limit your total intake of food on certain days. The highly popular 5:2 encourages you to normally eat for five days of the week and then, on the remaining two, to eat a calorie-restricted diet amounting to 600 calories for men and 500 for women. An alternative method is 16:8 fasting, where food consumption is limited to an eight-hour window.

Does IF lead to weight loss?

Proponents of IF strongly believe that fasting is the answer to weight loss and, indeed, there is scientific research that substantiates this claim. Study published in the International Journal of Obesity shows that women placed on a 5:2 diet achieved similar levels of weight loss compared to those on a calorie-controlled diet.

What are the health benefits?

Growing evidence points to enormous health benefits of IF. Let’s look at the facts.

IF reduces the risk of life-threatening diseases
While most studies on this topic have involved rodents, there is a firm belief that IF could improve biomarkers of chronic diseases in humans. A study in the American Journal of Clinical Nutrition concluded that IF might well have protective effects against diseases such as cancer, heart disease, and diabetes. It is believed that cells are placed under mild stress during periods of starvation and are consequently better able to resist disease. However, there is the widespread acknowledgment that more research is required.

IF improves cognitive function
There are some suggestions that IF may help protect against neurodegenerative diseases, such as Alzheimer’s and Parkinson’s, as well as improve memory and mood. IF is said to help improve neural connections in the brain while protecting neurons against the build-up of amyloid plaques associated with Alzheimer’s disease.

IF extends lifespan
Scientific studies point to IF enhancing lifespan; however, the majority of these studies use animals, so it is unwise to assume that the same results would apply to humans.

So are there any cons to IF?

There are plenty of reasons why IF is so incredibly popular, and yet, as mentioned above, much of the scientific research is animal based and requires further investigation. But beyond that, there are some negatives to IF. Those on this diet commonly complain of difficulty sleeping at night and concentrating during the day, dehydration and irritability. And obviously, there’s the risk of binging on normal eating days, just as there’s the risk of slipping into old habits following a calorie-controlled diet.

It’s fair to say there are definite pros and cons, and yet the massive potential benefits of IF are hard to ignore. It’s probably worth trying to ease yourself into a pattern of IF by starting with just one day of moderate fasting, then building it up to two. If it works for you, you could be on a win-win path to weight loss and good health.