The month of January is often devoted to the eating well and getting fit in response to overindulgence over the festive period.

One trend, however , has been popular enough to dominate social media feeds all year round and that’s clean-eating.

Search for #cleaneating on Instagram and you will find over 27 million posts.

But what actually is clean-eating?

What is it?

The concept on the face of it is relatively simple: the food you consume is as minimally processed as possible.

Some bloggers however, have come to align the term with more specific diets such as going gluten and dairy free.

The term is defined in the Oxford Dictionary as “Relating to a diet consisting of unprocessed, unrefined, and nutrient-rich food, typically eaten as small meals throughout the day”.

[Read more: What is the Milk Diet and does it work?]

What does the diet involve?

Those who practise clean-eating generally eat smaller meals throughout the day with plenty of snacks in between.

Meals are often prepared in advance and it’s often associated with fresh food including lots of organic vegetables and foods high in nutrients, cooked from scratch.

There is also emphasis on staying hydrated and drinking plenty of water throughout the day.

Why is it sometimes controversial?

Though well-intentioned, the craze has received some backlash online.

Many of its most prominent and influential backers are bloggers and not experts on nutrition and potentially misleading their followers.

There is also a feeling that deeming certain foods ‘clean’ implies others are ‘dirty’ and attaches shame and guilt to eating unhealthily, with some even claiming it is fuelling a rise in eating disorders particularly among young women and girls.

[Read more: 10 of the healthiest foods on the planet to eat now]

Why should I  avoid processed foods?

The core concept of the movement is to eat less processed food.

This is because these foods can be packed with excess sugar, fat and salt.

A simple way to adopt clean-eating is to choose wholegrain foods, add more vegetables to your diet and cut down on sugar.

How can I try it?

"A positive way to approach clean eating is to focus on basing your diet fresh and unprocessed food," explains Clipper Teas nutritionist, Libby Limon.

"Whole food is generally more bulky and naturally contains more fibre and water than processed food.

"Plants and plant based food is the backbone of your diet," she says, adding that you should include plenty of fruit, vegetables, nuts, beans, peas, pulses and wholegrains.

"Protein and healthy fats are also important, so for animal products choose organic and unpolluted dairy, meat and fish."

What impact will it have on my body?

"You will have less biochemically unrecognisable compounds such as trans fats, or artificial additives, exposure to toxins such as mercury, and generally a lower sugar and salt diet," Limon says.

"This will combine to energise the body from the inside out, giving it everything that it needs and less of the unwanted junk.

"In the medium to long term it may help protect you against ill health."

How do you stay healthy? Let us know in the Comments section below.