How to have a merry 5:2 Christmas - the dos and don'ts of festive fasting

Avoid feeling deprived by making smart Christmas meal food swaps, says Dr Michael Mosely. Photo / Getty Images

Fasting and the festive season don't appear to be obvious bedfellows, but according to Dr Michael Mosley, the 62-year-old creator of the 5: 2 diet, it's just about possible.

"First and foremost, the festive break is about togetherness, rejuvenation and joy," he says.

"That should be the guiding premise. But the all-too-well-known holiday cycle of overindulging, needing a nap, then waking up to start all over again suggests that it would be unwise to ignore the fact that overindulging is often followed by discomfort and guilt."

"The key thing about my approach to diet is not that it is not so much about deprivation. I am not an absolutist or a killjoy, so I recommend you plan to have fun and enjoy the choices you make. Zero tolerance will create frustration and distress. Be comfortable with your choices and compromises.

"Here are the questions I get asked most often in the lead-up to Christmas."

How can I still fast over Christmas?

"Over the festive period, I'll be sticking with a 6:1 plan. For me, it's really helpful to keep weighing myself because I know that much more than a 2 to 3kg increase becomes difficult to get off."

"But I do like to relax a bit so I just pick one day a week when I fast and reduce my calories down to about 800. I find that this seems to work if I also make fairly conscious choices around my food throughout the week.

"I'd also add in TRE (Time-Restricted Eating). More and more evidence is emerging that shows to get the maximum benefit from your diet, you need to take care of how you time your meals. Pioneering researchers such as Dr Satchin Panda, from Salk Institute in California, have discovered that by giving your body some daily downtime from the work of eating and digesting, you can unlock powerful repair pathways that protect against illness, ageing and obesity.

"Time-restricted eating is very straightforward. You simply ensure that for at least 12 hours within each 24-hour period, you do not consume any calories. Some people prefer to shorten their eating window further, to 10 or even just 8 hours."

"Most adults eat for about 15 hours through the day, which doesn't leave enough time for cell repair pathways to engage to their fullest extent. In one study, carried out with the help of the University of Surrey, two groups of healthy volunteers ate the same food, but the group on a time-restricted eating plan (eating breakfast 90 minutes later than usual, and dinner 90 minutes earlier each day) lost body fat and saw bigger falls in blood sugar levels and cholesterol."

"So yes, plan out your Christmas eating around your engagements to extend the fasting window as long as possible. Exercise in the morning, before breaking your fast, can also help extend the results of your fasting. HIIT (High Intensity Interval Training) is really helpful at this time of the year, and a big bang for your buck exercise that doesn't take too much time."

How can I make Christmas lunch healthier?

"Focus on all the vegetables on offer, making them the hero on your plate. Turkey is a classic Christmas meat and I certainly eat it, although these days I also pile on the vegetables. Turkey is a good source of protein and B vitamins (B3, B6 and B12) as well as zinc and magnesium. Although it is a good source of the amino acid tryptophan, which is a precursor to serotonin (the happy hormone), there is no evidence that eating it will make you either more cheerful or more sleepy."

Are nut roasts healthy or packed with calories?

"Although there is clearly a huge rise in interest in vegetarianism, this is not something I have yet embraced, full time. We are flexitarians, vegetarian a couple of days a week, so I wouldn't particularly recommend a vegetarian option on Christmas Day. I don't have a lot of experience with nut roasts, although I know they can be great when they include complex carbs, such as quinoa, as well as plenty of vegetables and chestnuts, walnuts, and Brazil nuts.

"They also sometimes contain eggs and cheese, so a lot of great ingredients, and some will have dried fruits such. So, overall, the nut roast can be delicious but worth keeping an eye on portion size as the calorie count will be quite high."

How about alcohol?

"For me, it's always going to be red wine. A glass or two of something you enjoy is perfectly acceptable and there are many reasons – beyond the science – that a glass of red wine can be good for your body and your soul. If you opt for a fizzy drink then be wary that the bubbles can make you drunk faster."

Festive meal food swaps to try

"There are ways you can happily eat with the rest of the family without feeling deprived by making some Christmas meal food swaps."

Turkey and ham:

"Lots of us enjoy ham and turkey, but try not to overdo the stuffing. Traditional stuffing recipes are very high in refined carbs. The more modern nut stuffings can be delicious but they are full of dried fruit which will cause big spikes to your sugar levels."

Red cabbage, carrots, Brussels sprouts, parsnips and potatoes:

"Focusing on vegetables is a great plan for a festive meal, especially the non-starchy varieties. I love red cabbage and cauliflower or celeriac (both are great roasted with a spoon of olive oil)."

Gravy, cranberry sauce, bread sauce:

"I'd be aiming to serve any types of sauces separately. They can pack a calorific punch and are often full of refined carbs. If you want to add some moisture to the meat, I would recommend some clear chicken stock or Dijon mustard."

Christmas pudding with brandy custard and cream:

"I find it hard to pass up on a small serving of Christmas pudding at this time of the year. If you want to swap for something there is an almost guilt-free chocolate cake on the Fast 800 programme website. Or try a chocolate mousse with fresh berries. "

Mulled wine:

"This tends to be stuffed with sugar and these days I prefer my red wine unadulterated. In fact, I recommend a glass of red wine as part of the Fast 800 programme. If you feel like the spices of a mulled wine, try adding them to warm water to make an exotic tea."

Canapés:

"Embrace the lean meats and seafood options. Opt for crudités. Avoid the baked items with too many carbs, like mince pies, and baguette-style offerings."

Nuts:

"Roasted chestnuts are a great suggestion. And nuts too – as long as not salted – are a good snack."

If you've had a big lunch, what's a better alternative to a turkey sandwich supper?

"Give your body time to rest and recover. What I find is that it's not the meal itself that is usually the biggest problem, it's the cravings it creates following the meal. So opt for a lighter meal. Maybe soup, scrambled eggs with spinach and avocado, or some smoked salmon, poached eggs and asparagus, which is enough to keep you satiated but not to trigger the cravings at the next meal.

"Lastly, if you fall off the diet wagon over the festive period, knowing that you can climb back on it is the most important thing. Don't beat yourself up and find the balance between indulging and overindulging. To get back on track, I would suggest:

1. Set fresh goals for 2020

2. Clean out the pantry

3. Get on top of your social calendar

4.Adopt a Mediterranean style of eating

5. Tell a friend

6. Increase your number of fasting days and add time-restricted eating

7. Track your results and keep checking in with yourself

"Giving some thought to how you want to feel over the festive break will help guide you in the right direction with every decision that comes your way."