Every January, the desire to adopt healthier eating habits is the most popular New Year's resolution. However, few of us successfully stick to our resolutions, so is it time that we allowed ourselves more flexibility?

[Read more: Here's how to make a pancake with just a banana and an egg]

In 2009, the launch of Paul, Mary and Stella McCartney's Meat Free Mondays campaign catapulted the term 'flexitarianism' into popular usage, and highlighted the value of being vegetarian for even just one day a week. So is it a fad, or does it make sense?

What is flexitarianism?

Health writer Joshua Zitzer says that, "with flexitarianism, there’s no need to go the whole hog — just go part-hog, and part-tofu."

It is the idea of being a 'part-time vegetarian', with a diet revolving largely around plant-based proteins. Animal proteins are also consumed, but to a lesser extent. More than 60% of millenials already consume meat alternatives, and the numbers of UK vegans rose by 350% in the decade between 2006-2016, illustrating our changing eating habits. Could flexitarianism be the lifestyle change you've been looking for?


How does it work?

Fans of flexitarianism claim the lifestyle is accessible, healthy and easy due to the non-restrictive nature of the diet – basically, nothing is off limits, and there are no strict rules.

Flexitarianism operates on an individual basis, and is adaptable to health needs, cravings, allergies, and budgets. So you can have a bit of bacon occasionally, but largely your diet will be packed with fruit and veg and meat substitutes.

What are the benefits?

It benefits animals and the environment. Up to 51% of global emissions are from the meat industry.

Vegetarian options are up to 60% cheaper than meat and are also less calorie-dense, meaning that, when not eating meat, flexitarians can eat more but still spend less.

Flexitarianism's emphasis on "new meat" - high-protein meat alternatives, such as tofu, lentils and eggs - means the diet also means cutting the health risks associated with high meat consumption, such as cardiovascular disease. Harvard studies estimate that vegetarians are 25% less likely to suffer from heart disease, a major killer of people in the UK.

Furthermore, adopting a flexitarian diet can help prevent and manage Type 2 diabetes and high blood pressure. Semi-vegetarians have lower obesity rates than their omnivorous counterparts, illustrating how reducing intake of animal protein can benefit physical wellbeing.

[Read more: Foods you definitely thought were vegetarian]

The key emphasis of flexitarianism is not on what you cannot eat, but rather on what you should add to your diet, particularly nutrient-rich, plant-based foods. This has the benefit of avoiding the prohibitive nature of many diet regimes such as the 'clean eating' movement, which has been criticised for tacitly implying that certain foods are 'dirty'. Flexitarianism allows everything in moderation, so you can listen to your cravings, although some flexitarians take the lifestyle more seriously than others.

What are the risks?

Dawn Jackson Blatner, a registered dietitian and author of The Flexitarian Diet, recommends that flexitarians take daily supplements to ensure they avoid deficiencies in essential nutrients, like iron.

Despite this, any deficiencies from a flexitarian lifestyle are typically due to a lack of understanding about which foods are nutrient-rich. If you are unsure, it is important to consult your doctor for guidance before making major changes to your diet. Flexitarianism, by its very nature, is a flexible lifestyle choice, but followers must make a conscious effort to plan nutritionally-sound meals and ensure that they remain nourished.

To find out more, visit theflexitarian.co.uk/