Ah, spring. The trees are budding, the welcome swallows are flitting southward, and the wellness gurus are once more urging us to give our insides a spring clean.

The spiel, like this one from Eating Well, goes like this:

“Seems like every spring, the urge hits to clean out, spruce up and simplify. We fling open our closet doors and toss out old shoes and sweaters, ready for a fresh start. So why not spring-clean your eating habits, too? Say goodbye to old routines and lighten up with nutritious foods – plus healthier, smarter ways to eat.”

Yeah! And the diet advice is on the money – for how we should be eating all of the time.

Spring, in all its colours, is a natural, is a boost to well being. It’s in winter we need to pay more attention to what’s happening with our bodies. Photo: Getty

Short version: drink lots of water, eat more salads, mushrooms, fruit and bitter greens, salmon and asparagus, and step away promptly from the sausage casseroles and mashed potato soaked with butter that made you so huggable in the winter.

The spring-cleaning advocates also suggest that now the sun is out, the days are getting warmer, get moving with a brisk walk. Really, the better advice is to exercise throughout the year. If it’s cold, put on a coat and a hat.

There’s also the idea that eating local seasonal produce is cheaper, better tasting, more nutritious – and even better for the environment because of the reduced carbon footprint caused by long-haul trucks and international travel. Here is a contrary view.

Drill down into the spring-clean argument from the well-being sector, and it’s often largely a symbolic one: the change of seasons is a good time to make some positive changes, to your wardrobe, your mood (hey sunshine, lift me up) or your diet. And that’s okay.

But there is an argument that warmer, friendlier weather provides an opportunity to recover from what winter has done to our bodies, as a natural course, and with our own neglect.

Here’s how the seasons affect our bodies

Our immune system: A 2015 study from Cambridge University found that our immune systems vary with the seasons. The researchers say this could explain “why certain conditions such as heart disease and rheumatoid arthritis are aggravated in winter while people tend to be healthier in the summer.”

The changing seasons have a profound impact on our bodies. Photo: Getty

The study found that the activity of almost a quarter of our genes (5,136 out of 22,822 genes tested) differs according to the time of year, with some more active in winter and others more active in summer. This seasonality also affects our immune cells and the composition of our blood and adipose tissue (fat).

The researchers were surprised to find that “a set of genes associated to an individual’s response to vaccination was more active in winter, suggesting that some vaccination programs might be more effective if carried out during winter months when the immune system is already ‘primed’ to respond.”

Does winter make us hungrier? This is an ongoing argument. A widely reported 2011 study from the University of Massachusetts Medical School found that study participants consumed about 200 more calories a day, beginning in the autumn when the days grow darker.

This was supported by a 1991 study that found “increased total caloric intake, especially of carbohydrate” in the autumn. This was associated with an increase in meal size and a greater rate of eating. The subjects “rated themselves hungrier at the end of the meal” in the autumn, even though “the larger meals resulted in a greater estimated amount of food in the stomach.”

The researchers argued that a decline in the number of daylight hours, starting in autumn, triggers people to eat bigger meals for the same reasons squirrels store acorns in trees: to provide food reserves as a survival mechanism against the dark and barren winter.

The counter argument is that winter provides more opportunities to eat because we spend more time indoors.

We’re not on the primal plains anymore

Our metabolism works against us in winter: As explained in an interesting article from Humanitas University in Milan, in winter “the human body naturally transforms to undergo an insulin-resistant state.”

This leads our liver to boost fat production, and our adipose and non-adipose tissues to store fat to prepare for winter. As it does for animals in the wild, this worked well for humans when we were hunting and gathering on the primal plains and food was scarce in winter.

Hunter gatherer societies have been found to have a healthier and more diverse gut microbiome because of a seasonal diet driven by availability in the wild. Photo: Getty

But it’s a problem when we sit out the winter with a fridge full of food.

In early spring, in healthy people, our metabolism returns to an insulin-sensitive state, and the body is less primed for storing fat.

But, according to a 2008 study, for many people, the attendant weight gain in winter, and the lack of exercise (no running around with a spear and a club) leaves them vulnerable to developing metabolic syndrome, a collection of conditions that often occur together and increase your risk of diabetes, stroke and heart disease.

The lack of exercise not only prompts weight gain, but it has a negative effect on mood.

The bottom line here: yes, please, embrace Spring as an opportunity to reverse some of the damage done by winter neglect. But don’t make it a short-term fix. Instead, use your spring-clean to build some momentum to eating well and exercising all year round.

To get you started, here’s an easy green spring minestrone recipe from the Heart Foundation.