Jo writes for Healthy Food Guide about health, medicine and wellbeing. She is also regular contributor to the Daily Mail's Good Health section and a former chair of the Guild of Health Writers. In 2018...

GP, author and presenter of BBC1’s Doctor in the House, Dr Rangan Chatterjee, believes that diet, along with rest, sleep and movement, is the pathway to good health. Here he shares his top five tips for healthy eating…

1. De-normalise sugar and retrain your taste buds. Overconsumption of sugar alters your taste buds. As we become used to it we just crave more and more, and it’s something we’re biologically wired to do. One Harvard professor of evolutionary biology says sugar is ‘a deep ancient craving’ that probably evolved to help us survive. But unrelenting sugar consumption sets us off on a blood-sugar rollercoaster and can lead to type 2 diabetes, so you need to cut back.

2. Eat five different vegetables every day of five different colours. Most people who try to eat five a day end up eating more super-sweet fruit. Try to retune your palate by eating mainly vegetables. A variety of colours is good for promoting bacteria diversity in the gut (the gut microbiome).

3. Consume all your food within a 12-hour window (so you have a 12-hour microfast every day). Micro-fasting (or autophagy, to give it its proper medical name) is a hot area of research I wasn’t taught about in medical school. It’s about giving the body a rest so that it has time to clean up. It’s your body’s chance to get busy with cellular repair, immune system repair and a host of other essential maintenance projects. Eating all your food in a restricted time window – for example, within 12 hours – allows your body to enhance its own natural house clearing. Reported health benefits of micro-fasting include improved blood sugar control, immune and mitochondrial function (mitochondria are the energy cells in your body), enhanced detoxification and Microbiota Accessible Carbohydrates (MCA) that feed on gut bugs. It also enhances appetite signalling (knowing when you’re hungry and when you’re full). This is a simple change most of my patients have been able to make.

4. Drink eight glasses of water a day (1.2 litres). The health benefits of drinking more water include increased energy, fewer headaches, better bowel function, clearer skin, fewer tummy aches, longer periods of concentration and reduced cravings for sugar.

5. ‘Unprocess’ your diet by avoiding any food product with more than five ingredients. I’m convinced that inflammation is the key factor in the epidemic of lifestyle-driven diseases. I believe damaged fats (such as vegetable oils, which can degrade when heated) as well as highly refined carbohydrates in our modern diets are driving much of this inflammation via the immune system. My advice is to eat more ‘real’ food as close as possible to its natural state to reduce inflammation, nurture our microbiome and help us to educate our immune system. All the world’s populations that are known for their longevity have a common factor in that they all eat minimally processed foods. Sticking to foods with five or fewer ingredients is a useful barometer for ‘unprocessing’ your diet. Challenge yourself to go for two weeks eating only fresh food.

Dr Rangan Chatterjee’s book, The 4 Pillar Plan: How to Relax, Eat, Move, Sleep Your Way to a Longer, Healthier Life (Penguin Life, £16.99), is out now.