The science of cravings: Why you want sugar, salt & comfort foods

It’s 9 pm. You’ve eaten dinner, you’re definitely not hungry… and yet somehow you’re standing in front of the cupboard negotiating with a packet of biscuits.

Or maybe it’s chocolate after a stressful meeting. Crisps during movie night. A giant bowl of pasta after the longest day ever.

Sound familiar?

Here’s the good news: cravings are completely normal.

They’re not a sign that you’ve “fallen off the wagon” or that you simply need more willpower. In fact, they’re your body’s way of responding to a fascinating mix of biology, psychology and experience.

Your brain, hormones, gut microbes, memories, stress levels and even last night’s sleep are all having a say in what ends up on your plate.

Let’s find out who’s really pulling the strings…

Hunger vs cravings: What’s the difference?

Hunger tends to build gradually. You may notice your stomach rumbling, your energy dropping, or that you’re ready for your next meal.

A craving can feel much more specific and often appears out of nowhere. You might suddenly want chocolate, crisps or something sweet even though you’ve recently eaten.

When you’re genuinely hungry, a nourishing meal may sound appealing.

When you’re craving something, only that particular food seems to hit the spot… Usually, it’s the one you promised yourself you wouldn’t buy!

Scientists believe that cravings are influenced by several systems working together – not just an empty stomach.

Your brain loves a reward

Your brain is brilliantly designed to remember things that help you survive.

For our ancestors, sweet foods were precious because they provided quick energy. Even today, eating sugar activates the brain’s reward system and triggers the release of dopamine¹ – a chemical messenger that helps us learn what feels rewarding and motivates us to seek it again.

That little burst of dopamine doesn’t just make the experience enjoyable. It teaches your brain to remember it.

Over time, your brain starts making connections:

Chocolate = comfort

Pizza = Friday night

Ice cream = celebration

The more often those pathways are repeated, the stronger they become. Eventually, simply seeing a chocolate bar, smelling fresh bread or feeling stressed can switch on those reward circuits before you’ve even taken a bite.

That’s why cravings can feel so automatic, and why they’re about much more than willpower.

Sugar activates dopamine pathways involved in reward, motivation and learning, reinforcing behaviours that previously led to pleasurable outcomes.² While this shares some features with other reward-seeking behaviours, it is not the same as drug addiction.

When stress sends you to the biscuit tin

Ever noticed you don’t crave broccoli during a stressful week?

There’s a reason.

When you’re under pressure, your body releases cortisol – often called the stress hormone. One effect of cortisol is that it can increase appetite and make calorie-rich foods seem especially attractive.

Thousands of years ago this was helpful. If life was stressful because food was scarce, eating energy-dense foods improved your chances of survival.

Today?

The “threat” is more likely to be traffic jams, overflowing inboxes and family logistics.

Unfortunately, your body hasn’t updated the software yet.

Chronic stress and elevated cortisol are linked with increased appetite and greater intake of high-fat, high-sugar foods.³

Why sugar is so hard to resist

Sugar gives us quick energy. But quick highs are often followed by quick lows.

When you eat lots of refined carbohydrates or sugary snacks on their own, blood glucose can rise rapidly before falling again. That drop often leaves you reaching for another biscuit… or another coffee… or both.

One simple way to avoid the rollercoaster?

Build meals that contain:

Protein
Healthy fats
Plenty of fibre
Whole-food carbohydrates

This combination slows digestion and helps keep blood sugar more stable.⁴

Is your gut whispering “cake”?

This is where things get really interesting.

Your gut isn’t just digesting lunch. It’s home to trillions of microbes that communicate with your brain through what’s known as the gut-brain axis – a two-way network that helps regulate hunger, fullness and even how rewarding certain foods feel.

Scientists have discovered that your gut can detect sugar almost as soon as it arrives. Specialised cells in the intestine act like tiny sugar sensors, sending rapid messages to the brain when real sugar reaches your gut.⁵ Remarkably, these cells can even tell the difference between real sugar and artificial sweeteners, helping explain why a diet drink doesn’t always satisfy a sweet craving in quite the same way.⁶

Your gut microbes may also influence appetite and metabolism by producing compounds that interact with the body’s signalling systems. While scientists are still working out exactly how much this influences sugar cravings in humans, it’s becoming increasingly clear that a healthy gut microbiome supports healthier appetite regulation,⁷ and may also play a role in shaping our food preferences.

The exciting part? Your gut microbiome isn’t fixed. Eating plenty of fibre-rich plant foods and fermented foods helps support a diverse community of beneficial microbes, and that may be one more way to work with your body, rather than against it.

Your gut is far more than a digestive organ – it’s a communication hub. It sends rapid messages to your brain through the gut-brain axis, helping shape appetite, food reward and even our preference for sweet foods.⁸

Why crisps are so hard to put down

Ever wondered why it’s almost impossible to eat just one crisp?

It’s not just about the salt.

Your body genuinely needs sodium. It’s essential for keeping your nerves firing, your muscles contracting and your body properly hydrated. Unlike sugar, there’s no substitute for it. That’s why evolution gave us a built-in salt appetite – a biological drive that helped our ancestors seek out this precious mineral when it was scarce.⁹

But modern ultra-processed foods take things a step further. Food manufacturers don’t add salt simply to make foods taste salty. Salt reduces bitterness and brings out sweet and savoury flavours, making foods more enjoyable to eat.¹⁰ Combine that with fat, refined carbohydrates and that irresistible crunch, and you’ve created what food scientists call a hyper-palatable food – a combination of ingredients that makes foods exceptionally rewarding and difficult to stop eating.

That’s why a bag of crisps can disappear so quickly.

But biology is only part of the story. Over time, your brain also learns to associate certain foods with relaxation, comfort and good company. Before long, movie night doesn’t feel complete without a bowl of crisps beside you.

There’s nothing wrong with enjoying these foods from time to time. The key is recognising why you’re reaching for them. Is your body asking for nourishment, or has your brain simply linked crisps with switching off after a long day?

Sometimes, what we’re really craving isn’t the salt at all. It’s the experience.

Understanding that difference helps us enjoy these foods mindfully – without guilt, but without falling into the trap of letting habits or highly palatable foods make the choice for us.

Why comfort food really ‘comforts us’

Have you noticed how certain foods feel like a hug?

That’s because food isn’t just fuel. It’s memory.

A bowl of soup might remind you of being cared for when you were ill. Fresh bread may take you back to your grandmother’s kitchen. Chocolate might bring back birthdays, celebrations, or simply surviving a particularly difficult Tuesday.

Here’s the fascinating part: comfort foods aren’t universal – they’re learned.¹¹ Your favourite comfort food isn’t comforting because of what’s in it. It’s comforting because your brain has linked it with feelings of safety, warmth and connection over many years.

Scientists call this associative learning.¹² Every positive experience involving food strengthens those memories, so the next time you’re feeling stressed, lonely, or exhausted, your brain naturally reaches for the foods it remembers as comforting.

That’s why one person’s comfort food is chicken soup, while someone else’s is cheese on toast or a takeaway curry.

Sometimes, what we’re really craving isn’t the food itself. It’s the feeling that comes with it.

Our brains form powerful associations between food, emotions, and social experiences. These learned memories can influence food preferences and cravings long after the original experience, helping explain why comfort foods are deeply personal.

Why everything looks tastier after a bad night’s sleep

Ever noticed that after a poor night’s sleep, the biscuit tin suddenly becomes much harder to ignore? That’s not just because you’re tired.

When you don’t get enough sleep, your body starts sending mixed signals. It produces more ghrelin – the hormone that tells you it’s time to eat – and less leptin, the hormone that helps you feel full.

At the same time, your brain’s reward centres become more responsive to tempting, high-calorie foods.¹³ Suddenly, the office doughnuts, the chocolate bar at the checkout, or last night’s leftovers seem far more appealing than they did yesterday.

It’s your body’s way of trying to find a quick source of energy when it’s running low.

The good news? One restless night won’t undo a healthy lifestyle. But making sleep a priority is one of the simplest and most overlooked ways to support healthy appetite regulation and reduce those “I need sugar now!” moments.

Before you raid the biscuit tin…

Next time a craving appears, pause for a moment and ask yourself:

Am I actually hungry?
Am I thirsty?
Am I stressed?
Am I tired?
Am I bored?
Do I just need a break?

Sometimes your body genuinely wants food.

Sometimes it wants rest.

Or a walk.

Or a hug.

Or simply five quiet minutes.

Learning to tell the difference is one of the kindest things you can do for yourself.

Work with your body, not against it

At Chuckling Goat, we don’t believe cravings are the enemy. They’re information.

The more we support our bodies with diverse fibre rich foods, fermented foods, quality protein, healthy fats, good sleep and stress management, the easier it becomes to find balance.

Will cravings disappear completely?

Probably not. They’re part of being human.

But understanding why they happen helps us respond with curiosity instead of guilt – and that’s where lasting change begins.

Because health isn’t about fighting your biology. It’s about learning to work with it.

If you’d like some practical, gut-friendly strategies you can start using today, check out 5 easy ways to curb cravings & stay on track.

Any questions? Contact one of our Nutritional Therapists via live chat, weekdays from 8 am to 8 pm.