Intermittent fasting

Intermittent fasting fad or fact?

by Katherine Gudgin

Many studies show that leaving sixteen hours between meals is good for you. Eating well before bedtime is also recommended. For those who want to change their habits, it’s best to do so gradually, ensuring good nutrition and exercise.

One of the eating plans that has gained a lot of traction in the past few years is intermittent fasting. Fundamentally , it restricts the period of time when you can eat rather than what you can eat. Usually this requires either a 16-hour gap with no food or two 24-hour periods each week when you eat either nothing or extremely limited calories.

How does this work? A variety of animal and some human studies have shown that alternating between times of fasting and eating is good for the health of your cells. It may trigger the kind of ancient processes designed to help us when food was scarce. The process is called metabolic switching.

Essentially, when there is no food in your digestive tract, your body flicks a virtual switch, uses up rapidly accessible, sugar-based fuel in your cells and thereby converts fat to energy. This switch changes cells and hormones that regulate your blood sugar levels and increases growth hormone levels that maintain tissues and organs. It may also increase your resistance to stress and suppress inflammation.

Does it work?

Studies on intermittent fasting have been short-term with a small number of participants. Most studies have found that those who follow any kind of intermittent fasting diet lose weight compared to those on a normal diet. However, intermittent fasts don’t tend to result in more weight loss than conventional calorie-restricted diets.

One research programme noted a high dropout rate of 38% probably because controlling what you eat is hard, regardless of the regime you follow, and with intermittent fasting people have a tendency to be “good” on fasting days and then indulge on non-fasting days. Your body doesn’t like to be deprived of food.

Are there benefits other than losing weight?

Some studies with animals indicate that intermittent fasting could help lower the risk of cancer, decrease blood pressure and blood lipid levels, reduce resting heart rates and perhaps

slow ageing. The reason for all of these may be that fasting activates cellular mechanisms that boost immune functions and reduce inflammation, thought to be a key indicator for a wide variety of illnesses. However, most doctors conclude that reducing body fat in any healthy way will help you improve your cardiovascular function and metabolic profile, thus reducing risks.

There are also studies which indicate that intermittent fasting can change risk factors associated with obesity and diabetes. Two studies in the UK of 100 overweight women show that although the women who fasted intermittently lost the same amount of weight as those on a caloriecontrolled diet, they out-performed the control group in terms of insulin sensitivity and stomach fat reduction.

Doctors running a trial at Boston’s Brigham and Women’s Hospital commented on the psychological benefits for patients who didn’t want to track calorie intake or record food consumption. With intermittent fasting this is not necessary. However, they also noted that as long-term weight-loss success requires changes in food and eating patterns, intermittent fasting may not be a sustainable solution. More research is needed for definitive findings.

What should I know?

This diet is not for everyone. It can involve skipping meals and limiting your calories to “starvation” levels so it is not advisable for women who are pregnant, are trying to get pregnant or are breastfeeding. Anyone with a condition like diabetes, heart disease or high blood pressure should consult their doctor before considering intermittent fasting because it can make electrolyte levels abnormal.

You are also likely to be irritable for the first few weeks as your body and brain get used to the new routine. But apparently there are benefits even for those who don’t need to lose weight. At the University of Toronto, a study involving 220 healthy, non-obese adults showed improved memory skills. Worth having!

Alternate Day Fasting

l On fast days, no food or beverages with calories l Rotate days of eating and fasting l On non-fast days, eat what you like as long as it’s healthy

Time-restricted* Fasting

l Consume no calories for between 8 to 16 hours every day l Time between meals can vary

* Easier for those who don’t snack after dinner and are able to eat immediately after getting up