Intermittent Fasting
Intermittent fasting
What is intermittent fasting?
Intermittent fasting encompasses several different dietary behaviours, all of which focus on controlling the period in which food is consumed. These behaviours dictate a fasting and feeding schedule of various lengths. However, there isn't a restriction placed on the TYPES of foods consumed during feeding times.
What are the types of intermittent fasting?
5:2 Diet: one of the most popular intermittent fasting diets which involves a ‘normal’ healthy eating days for 5 days a week and ‘fasting’ for 2 days a week. On these ‘fasting’ days you eat one-quarter of your usual meals, which is around 2100 – 2500 kJ (or 500-600 calories). Fasting days can be consecutive or separated throughout the week.
16/8 Method: involves restricting your meals to an 8-hour window each day (e.g. 12pm – 8pm) and fasting for 16 hours.
Eat-Stop-Eat: involves fasting for 24 hours, once or twice a week.
Potential benefits of intermittent fasting
Weight loss.
Contrary to what you may expect, early research shows that people do not over-consume kilojoules on non-fasting days.
May curb food cravings.
May help you tune into your hunger signals.
May reduce inflammation.
May improve cholesterol levels.
Potential downsides of intermittent fasting
The quality of your diet may not improve, since you are not educated around what types of foods to eat or not eat.
Constant kilojoule restriction isn’t easy nor practical for many of us in the long term, so you may not sustain the diet long enough to see results.
There is limited evidence about the long-term effectiveness or health issues related to intermittent fasting.
You may experience headaches, fatigue, extreme hunger and low energy levels on fasting days. This may make it difficult to concentrate, perform at your best.
Other side effects can include constipation, bad breath, gall bladder disease, gout and liver inflammation.
A smaller total number of meals means there is less opportunity to get essential nutrients in if you do not plan carefully.
May slow your metabolism – some fasting diets appear to slow metabolism to conserve energy. This might mean you gain even more weight when you finish.
Designated fasting periods may make it difficult to participate in the social sharing of a meal.
There is no mention of exercise, and many may find it difficult to exercise on fasting days.
Intermittent fasting and weight loss
Overall, the it appears that intermittent fasting can promote weight loss, however it does not necessarily outperform daily calorie restriction for weight loss. Some researchers are suggesting it might be a viable option for those who struggle to maintain consistent daily calorie restriction for weight loss, however there may be lifestyle barriers to using intermittent fasting as a long-term, sustainable weight loss method. The research so far has not found that fasting increases metabolism or improves food choices. The question to ask yourself is - can you really sustain yourself for a long period of time on this diet? Therefore, while it may cause short-term weight loss, as with most diets, in the long term it is unlikely to be an effective weight loss strategy.
Who should not try a fasting diet?
Fasting diets are not for everyone. People with major medical problems, or taking a range of medications including insulin, should not go on them, unless under medical supervision; they are not suitable for children, in pregnancy or for people with eating disorders; and they may exacerbate some mental health conditions.
Bottom Line
While intermittent may help you to lose weight in the short term – the long-term effectiveness and health benefits are yet to be understood It is important to understand that all diets essentially result in weight loss by ensuring that you eat less kilojoules than you spend – they’re just different means of doing so.
The main thing you need to consider is whether the diet is sustainable in the long term for you. Our approach is to adopt healthy eating habits that you can sustain for life and which nourish you rather than restrict you to certain foods. To figure out whether intermittent fasting is your match, make an appointment to see one of our Dietitians.