My two-week plan to reset your health, lose weight and feel great – by the royals' nutritionist

Nutritionist Gabriela Peacock has a two-week plan to kickstart a healthy September. Photo / Getty Images

There are, of course, many ways to approach a health kick. I favour a gentle approach rather than giving clients (or myself) an immediate uphill battle by ditching whole food groups.

Here are my tips for a simple September health reset to help you look and feel better for the season ahead.

Make fasting work for you

Intermittent fasting is eminently achievable and works. The 16:8 approach involves eating within a window of eight hours each day – and fasting for the other 16 hours – and is an extremely effective way to lose weight healthily. Fasting lowers inflammation and helps improve the rate of cellular repair, so it's helpful for rebalancing all sorts of things in our bodies, from autoimmune disorders to chronic pain, injuries and fatigue. It also boosts immunity by giving the body a bit of a shock, which is helpful in the lead-up to winter. Unlike crash diets that are hard to maintain, it's also very sustainable. All you need to do is pick your eating window.

Work out what is most likely to suit your routine and your energy levels. For instance, do you struggle to get by without breakfast, but don't find you need much dinner? Perhaps 9.30am to 5.30pm would work for you. Or if you think you can last until late morning and want to be able to eat dinner at a normal time, 11am-7pm might work better. There is no additional calorie counting, you just pick your window and avoid eating outside those hours.

You can choose to eat three small meals in the eating window, or two larger ones. Just try to keep the window the same every day as routine is helpful for balancing the body's processes.

Try to keep it up for two weeks and see how much better you feel.

Cut alcohol down to a once a week treat

Just practising intermittent fasting will help you lose weight and start to feel better quickly, but if you really want to make a difference, you'll need to make changes to your diet too. That doesn't mean restricting yourself hugely; small tweaks can go a long way.

When fasting, balancing your blood sugars is important so you don't have energy peaks and crashes. The best way to do this is to include protein with every meal. Don't just have a piece of toast for breakfast, have it with an egg or smoked salmon. Fish, poultry, eggs, avocados, nuts, cottage cheese ‒ adding good protein to every meal will ensure your blood sugar doesn't spike, leaving you buzzing for an hour and crashing soon after. Have a balanced breakfast, and you won't be craving carbohydrates two hours later.

It'll also help you sleep better if you have protein at dinner time, particularly if you opt for the kinds of protein rich in the amino acid tryptophan, like cottage cheese, poultry and chickpeas. These are particularly good as they boost our serotonin, which then creates melatonin which helps us sleep better.

Increase the amount of variety in your fruit and vegetable intake too. Aim to eat the rainbow ‒ blueberries with their fibrous skins, filled with antioxidants, red peppers, broccoli, kale. A range of colours will increase the number of phytonutrients (the chemical compounds in fruit and veg) in your diet, which is great for immunity. It'll also inevitably increase the amount of fibre you're consuming too, which will help to support good gut health while also keeping you full for longer.

If you can, cut out booze for a couple of weeks as it plays havoc with sleep and it is full of sugar and empty calories – if you really want one drink, have it as a treat once a week.

Our liver cleanses our body but it needs nutrients to do so efficiently, so if you have been drinking lots over the summer months, up the antioxidants in your diet to give your liver a boost.

Don't go cold turkey on sugar

Don't worry too much about snacking ‒ it's all about eating in a balanced way that maintains your energy levels through the eight-hour window, and that doesn't necessarily mean avoiding all temptations. But try to swap biscuits and chocolate for healthier, less sugary options. Just make sure those options are things you actually want to eat.

Think of it as reprogramming, not going cold turkey. Dark chocolate covered nuts, houmous and crudites, roasted chickpeas ‒ have things around that you're likely to reach for and enjoy, and that contain some protein rather than giving you a blast of pure carb and sugar. And if you're really missing your summer icecreams blitz yogurt and berries with a bit of honey and freeze it for a healthy alternative.

Sort out your sleep

Often, over the summer, we find we don't sleep that well. We're in strange beds, struggling with heat and have usually had one glass of wine too many. It all contributes to a disturbed sleep pattern, and when getting our health back on track, sleep needs to be at the top of our priority list.

If we don't sleep enough, our stress levels are likely to increase. Stress then causes our bodies to produce cortisol, which prevents us sleeping well. People who don't sleep well will find it harder to lose weight, as cortisol makes the body think it needs glycogen and causes it to use up blood sugars instead of burning fat.

Try cutting down on your caffeine intake while you're fasting to help with those blood sugar dips and improve your sleep. Or try green tea, which has some caffeine but is also rich in antioxidants.

Finally, I recommend taking a good quality multivitamin, or at least magnesium, which is fantastic for sleep. It's one of the first minerals you lose when your diet isn't great and you're drinking a lot.

• 2 Weeks To Feeling Great by Gabriela Peacock is out now.

- As told to Eleanor Steafel