Intermittent Fasting (IF) is popular for its perceived health benefits & for weight control
What is intermittent fasting?
Intermittent Fasting (IF) is the principle behind diets such as the 5:2 and 16:8 where the eating time window is restricted.
With 5:2 fasting, people eat normally for five days a week and fast on the other two days by consuming just 25% of their calorie needs (500 calories for women and 600 calories for men) on fasting days.
16:8 fasting is a version that restricts eating to an eight-hour window such as from 7am to 3pm. During this time, it's recommended to eat and drink freely then during the 16-hour fast simply to keep hydrated.
Alternate day fasting (ADF) involves switching between alternate days of total fasting or consuming just 25% of calorie needs and days of free eating.
Research view of fasting diets
Reducing time spent eating will naturally restrict calories and this straightforward approach appeals to some. It doesn’t exclude food groups or require a calorie count, meaning it's easy to stick to and can increase the chances of success.
Compared to other types of weight loss programmes, evidence for the effectiveness of IF is limited. Some consider diets such as 5:2 as fad diets that are unbalanced and bad for health.
Studies so far suggest no greater weight loss compared to continuously restricting calories daily. Both intermittent and continuous periods of calorie restriction bring about beneficial metabolic changes in the body, affecting risk factors such as insulin sensitivity, blood fats (lipids) and improving blood pressure.
Champions of the diet advocate such changes to reduce the risk of developing chronic diseases such as type 2 diabetes and heart disease. Further research is needed to confirm the benefits and whether IF is a safe and sustainable option for the long-term.
Intermittent fasting watch-outs
Not everyone can fast safely and there are also common side-effects such as dizziness and fatigue to manage. Don’t forget that healthy food choices, avoiding feasting, keeping hydrated and regular physical activity are encouraged to support a balanced diet and healthy lifestyle.
