What you should know about your appetite this time of year.

For a lot of us, the cold weather and dark mornings of the winter months equal cravings for “comfort food” and the increased desire to sleep in. 

It’s bliss, really. Who doesn’t love a giant bowl of pasta and glass of red wine, and a Saturday sleep-in on a chilly morning?

On the flip side; opting for healthier options and living a more active lifestyle seems to become a lot easier when summer rolls around. In fact, most people would say they actually feel less hungry when it’s hot outside.

So why do the rich food cravings seem to subside in summer? Is it our bodies telling us we don’t need the extra calories for energy to warm up, or simply a new craving arising for fresh, vibrant meals?

I consulted two experts to find out if the seasons actually have any impact on our appetites, and what they had to say was very interesting.

Listen: The problem with saying “summer bodies are made in winter”. Post continues after audio.

Nutritionist Jennifer May said the noticeable change in appetite from winter to summer was likely due to the production of cortisol and serotonin.

Cortisol, a hormone which gives us energy, is produced with stimulation from sunlight, while serotonin makes us feel calm and is stimulated by starchy foods such as carbs, Jennifer explains.

“Cortisol is produced each morning between 5-7am in a healthy human,” she said.

“(It) wakes us up, gives us energy, motivation and appetite, cortisol is also a stress regulator. Too little and we have no ability to deal with stress, too much and we are overstimulated and stressed. Cortisol has a key impact on our digestion, metabolism and appetite. With too much cortisol we feel hungry for quick energy – typically carbs, which stimulate the production of serotonin.”

Jennifer explained further:  “Serotonin makes us feel calm and at peace. So you can imagine that if you’re stressed and anxious, eating something starchy or sugary to release serotonin (calming) will balance you and help you return to neutral.”

So what does sunlight have to do with the production of cortisol, our stress regulator?

“One of the reasons our eye lids aren’t completely opaque is so that the suns rays can enter the eyes on sunrise and stimulate the production of cortisol, which in turn should wake us up feeling great,” Jennifer says.

“This is why humans should be rising with sunrise and sleeping after sunset.”

Interesting.

She added that research indicates serotonin production is stimulated by sunlight, too.

This means in winter, with its dark mornings and our tendency to stay indoors and out of the cold, we have less exposure to sunlight - therefore lower cortisol and serotonin production.

This, in more serious cases, Jennifer explains, is what leads to some people developing Seasonal Affective Disorder, or SAD.

"In winter we mostly wake in the dark, leave home before sunrise, sometimes even are locked inside all day leaving again only when it's dark again. This leads to lower natural cortisol production," Jennifer says.

"Research shows that we produce more serotonin on sunny days. Winter, with reduced hours of sunlight, and weather conditions which may keep us inside, may lead to very low levels of serotonin, leaving us depressed, fatigued and unable to tolerate stress," she added.

"Some may develop a more serious version of this called Seasonal Affective Disorder or SAD. Even at a milder level however, this means stress may feel more stressful... As a result, we'll probably crave sugar and starch to help promote more serotonin production - to make us feel happy and calm again."

Jennifer also said that as we tend to be less active in winter, we experience less endorphins - which we then chase from food, instead.

However, accredited practising dietitian from the Body Doctor, Naras Lapsys, put simply, says no. He doesn't think the weather affects our appetite.

Rather - it's external factors that lead us to crave certain food groups when it's hot or cold.

"In winter we seek comfort in food, and naturally the comfort food is richer, and more loaded with calories," he said.

"People like rich food because it feels like it warms them up. I don't think it's anything other than the fact that we as humans like comfort.

"When you eat a warm food, it's very common for it to be more rich - it might be slow cooked, or a warm soup with copious amounts of bread, or full of cream and sauces."

"It's more about the warm meal being an avenue to more calories than something internally in the body affecting our appetite."

He said in summer, we simply don't feel as though we need to be warmed up, so we naturally opt for the less-calorific meals.

He also said that dehydration and humidity may often lead us to drink more, rather than eat.

Jennifer reflected this opinion.

"In summer it's all about replenishing electrolytes and keeping the body cool," she said.

"Digestion creates heat, so on particularly hot days we may not feel like eating much. which could heat us up more. This is why we crave fruit and fresh salads which are rich in electrolytes and also provide lots of water to keep us hydrated and cool. They are also fairly low effort to digest so less taxing on an overheated body."

Naras added that the availability of fresh food in summer altogether made it easier to eat healthier, thus easier to lose weight. However, he queried whether drinking more could lead to consuming more sugar, as well as alcohol.

He also believed that when it comes to exercise, "it's all relative".

"In summer it's warm, it's not raining as much - it's a hell of a lot easier to get out and be active...but there are a lot of people who do exercise all year round, it just depends on the person."

"I honestly think it's way more external than internal," he concluded.

"Whatever impact it might have within the body's mechanisms will have a small impact - the major drivers are what's happening externally, and what's available to you in terms of different foods."

Jennifer, however, had two more possible explanations to our change in appetite from summer to winter.

Namely Vitmain D levels, and the calories required to heat and cool our bodies.

"Vitamin D is made in our body as a reaction to absorbing the suns rays. During winter we make less vitamin D due to lower sun exposure, if we start winter with lower levels we can become quite deficient. Researchers have studied the effects on Vitamin D and calcium in obese patients. They found that those who had higher levels typically had more control over their appetite and reduced tendency to overeat or binge," she said.

"Finally, there's also the effects of the weather itself, we use more calories during winter if we're exposed to colder temperatures as it takes more calories to heat the body.

"Those who live in locations with seasons will often find themselves eating more throughout winter just due to this reason alone. However, when we take into account all the extra information above and the complex interplay of our hormones on our nutrition, it's easy to see why we don't just want to eat more, but also eat differently," she surmised.

While both Jennifer and Naras' opinions suggest that it's likely we will eat more in winter, due to availability of certain foods, our body's seeking comfort, and our hormones, there are ways around it.

"Regular exposure to sunlight, keeping your blinds and curtains open at night if possible so you wake with the sun's rays, eating foods rich in Vitamin D (such as egg yolks, butter, salmon), exercising regularly and keeping your caffeine consumption to a minimum (will help)," Jennifer says.

"Eat carbohydrates as part of your healthy diet but do so with healthy ones - brown rice, sweet potato, potato (yes potatoes are healthy too) and legumes.

"Plus plenty of fresh fruits. Eating locally and seasonally also helps - the fruits and vegetables grown in each season typically are more rich in the nutrients required to support you through that season."