Experts have also found that restricting food intake during the day can help prevent health problems such as high cholesterol, heart disease and obesity, as well as improve mental health and wellbeing. By not consuming any food, our body is able to concentrate on removing toxins, as we give the digestive system a rest. Nutritionist Claire Mahy told Al Jazeera: “Fasting allows the gut to cleanse and strengthens its lining. It can also stimulate a process called autophagy, which is where cells self-cleanse and remove damaged and dangerous particles.” Scientists have also been studying the link between diet, gut health and mental wellbeing and, as Mosley explained, fasting can lead to the release of BDNF (brain-derived neurotrophic factor) in the brain. “This has been shown to protect brain cells and could reduce depression and anxiety, as well as the risk of developing dementia,” Mosley added. Many people who have embraced fasting have also found that, done properly, it has helped them lose fat and gain lean muscle mass.