As well as promoting weight loss, intermittent fasting has been associated with a variety of health benefits, from improving diabetes management and reducing inflammation through to extending your life. While most human studies are still short term, current research is promising.
Intermittent fasting cuts your overall kilojoule intake, so you’re likely to lose weight. “Intermittent fasting can help with visceral [belly] fat loss while sparing muscle mass,” Jamie Chambers says. “This is important for long-term weight management, as higher muscle mass helps to burn more kilojoules at rest.
“When intermittent fasting was put up against a traditional kilojoule-controlled diet, in many cases intermittent fasting gave the same or better results, particularly in overweight and obese people.”
Importantly, intermittent fasting seems to teach people that it’s okay to feel hungry sometimes.
A fear of hunger can cause problems for some people who need to lose weight, and is sometimes associated with overeating. But those who try intermittent fasting say that knowing that they’ll have food at a certain time relieves this fear and anxiety.
There’s now increasing evidence that practising intermittent fasting may be beneficial to people who have diabetes, and that it can also be done with safety.
“Intermittent fasting may help reduce blood glucose and insulin levels,” says Chambers. “The most significant impact may be on people with pre-diabetes, where studies have shown that insulin resistance reduced by up to 40–45 per cent. Non-diabetic overweight adults also recorded a 20 per cent reduction in their insulin levels.”
It seems our gut bacteria like short periods of fasting. Most of the research is animal-based, but recently a few trials with humans have shown fasting can decrease the bacteria associated with inflammation and increase bacterial diversity — two important features when improving your gut health.
Time-restricted feeding has a lot do with changes to your gut bacteria. Gut bacteria are affected by day-night body patterns (circadian rhythms). If your body has periods without food overnight, it can help re-establish disrupted circadian rhythms, improving gut health.
Fasting also benefits your memory and mood. “Fasting can help to protect your brain from neurodegenerative diseases like Alzheimer’s and Parkinson’s disease by ‘shocking’ the brain to create new neurons,” Chambers says.
“These new neurons are more resistant to plaque accumulation, which is related to the progression of these diseases. Fasting may also make changes to the brain that improve memory and mood by stimulating the growth of new neurons and strengthening neural connections.”
Your heart might benefit, too. “Fasting has been shown to help reduce ‘bad’ cholesterol levels and blood pressure, reducing your risk of heart disease,” says Chambers. “Research has shown that fasting can reduce triglycerides by up to 25 per cent over 12 months. It also showed a reduction in systolic blood pressure [the pressure in your blood vessels when your heart beats] over three months.” ■