Why Do People Overeat?

True hunger… the desire to seek out enough energy and nutrients to meet your body’s needs It is a hard-wired, evolutionary survival mechanism. So what is it that causes us to consume food BEYOND – often WAY BEYOND what is good for us? Let’s find out why we overeat!

Table of Contents

Overwhelming Urge to Eat

Have you ever had an overwhelming urge to lick an ashtray? Pretty disgusting right? Back when I was in my final year of training to become a GP, I had a patient who came to me. She was pretty embarrassed about the fact that she had an overwhelming desire to lick ashtrays and eat cigarette ash.

She wasn’t a smoker and she really didn’t like doing it, but she couldn’t fight the urges she was having. I hadn’t seen anything quite like this before so I asked one of the more experienced doctors who told me to run some blood tests. And sure enough this woman had a pretty significant iron deficiency anaemia.

Her cravings to lick the ashtray was her body trying to get the nutrients she needed. Turns out this kind of behaviour is well documented. Needless to say that this woman much preferred the flavour of the iron tablets that I then prescribed for her and she stopped licking ashtrays.

A more familiar example is the cravings that women get during pregnancy. Pregnancy is very demanding on the body and therefore a lot of good nutrition is needed and cravings for unusual foods during pregnancy is about finding specific nutrients that the body needs.

So our bodies are hard-wired to change our behaviour in ways that satisfy our basic nutritional needs even though some things can present themselves in unexpected ways.

You’d think that we’d have some sort of system within the body that would stop us from simply overeating beyond that which can lead to obesity and type 2 diabetes, both conditions which have become so prevalent in recent years.

And to a certain extent, we do. But they’re relatively weak and unfortunately all too easily overridden.

It is only very recently in human history that we’ve had an abundance of food and so we’ve never really evolved to deal with this.

So what is it that causes people to go beyond this innate sense of hunger? Let’s find out!

Conscious Overeating

Conscious overeating would involve making a conscious decision to eat, despite not being hungry. Now while this might be a conscious decision – it doesn’t necessarily mean it’s a good decision.

I think that for many people eating breakfast is one of these. I used to force down breakfast every morning despite not being hungry due to the belief that it is the most important meal of the day.

We were misinformed by the marketers at breakfast cereal companies that breakfast is the most important meal of the day, and you really need to eat it because it’s going to kickstart your metabolism.

Many people force down food when they’re not hungry on the false belief that it’s important to do so.


Now breakfast is a bit of a divisive subject and I know that some of you are already getting ready to write a comment on this post and tell me that you ARE hungry in the morning and that you like to eat breakfast.

Great! I want you to comment. In fact, I’d love to take a bit of a survey of everyone who is reading this post as to whether or not they actually are hungry in the morning when they wake up.

So feel free to just write Hungry or Not Hungry in the comments below.


Breakfast has long been marketed as the most important meal of the day. You’ll probably notice that many of the cereal manufacturers also now sell brunch bars and tell you not to go hungry between breakfast and lunch!

Think about after exercise recovery drinks – do you really need to consume a sugary drink to replenish the body after a workout! Unless you’re an elite athlete with specific training needs, absolutely not.

Smoothies – especially commercially prepared ones – are often a very efficient way to get a vast amount of sugar into your body very quickly.

So there is a lot of misinformation out there about when to eat, and what is healthy and much of that comes from the food industry.


On a certain level it can be as simple as – I’m not hungry, but there is a cake there, I like cake, I want that cake, so I’m going to eat that cake.

I hope it doesn’t come as a surprise to you…. But Food is nice and eating it is very enjoyable and the nicer it is, the more likely we are to over-consume it.

Do we need to drink anything other than water? No – but we do, in part because it’s pleasurable.

One of the chemicals in our brain, dopamine, plays a significant role in pleasure-seeking behaviour, and the more pleasurable a food, the bigger the dopamine hit, the more we will want to seek it out.

So what makes foods particularly pleasurable?

It’s usually a combination of different factors blended to varying degrees.

  • Sweetness
  • Saltiness
  • Fattiness

Think of a buttery, salted caramel?

Is the texture also important? Think of the way chocolate is solid at room temperature but melts in your mouth!

Food scientists try really hard to perfect this combination of factors to make the perfect food. They call this the Bliss Point and there are large research and development departments that have become really good at giving us food that we just want to eat more and more of.

Now, this is great for a food company that wants to sell more and more food.

But the result is ultra-processed foods that are high in refined carbohydrates, high in fat and very energy-dense whilst offering little in the way of nutrition.

This just happens to be the worst kind of food for the human body and over time causes weight gain and starts us on a pathway towards type 2 diabetes.

Are All Processed Foods Bad?
Ultra-processed, hyper-palatable foods are easy to obtain as they seem to be everywhere and are often very cheap compared to healthier, less processed foods. You often don’t have to cook them, you just open up the packet and there you go!


Many people will also have grown up with food as a reward for good behaviour and again, dopamine is very important here.

We learn Good behaviour = dopamine hit that’s reinforced over the years.

Reward sign

Of course, many adults use food as a reward too. I often exercised as a justification for reward-based overeating. I did this in the gym so therefore I can go and have that!

Unfortunately, despite what we’re frequently told – we can’t simply replace calories burned with calories earned. The body just doesn’t work like that. But even if we could, people WAY overestimate the reward they could have based on the amount of work they have done!

Habitual Eating

In a perfect world, true hunger would have us eating when we’re hungry, and drinking when we’re thirsty.

But in reality, we eat when we always eat and we mostly drink when we eat too.

There are hormonal changes in our bodies that occur around the times we normally eat to prepare our bodies for eating and digestion.

These are learned responses and are reinforced by repetition.

Going back to the breakfast example. Eventually, I basically made my body learn to be hungry in the morning.

And if you eat a large meal at 7 pm every evening, your body will prepare for a large meal at 7 pm every evening.

If you always eat something sweet after that meal, your body will expect something sweet after that meal.

But importantly these learned responses can be unlearned and much to many people’s surprise if the meal never actually comes, the hormone levels that are making you hungry actually subside, you don’t just go on getting hungrier and hungrier until you eat.

Food Addiction

Now, whether or not you can be addicted to food in the same way you can be addicted to other substances is the of many arguments amongst doctors and scientists. I really don’t want to get into that because quite frankly it’s boring.

Whether or not it is true addiction or not it is clear that people show Addiction Like Behaviours with food.

The criteria for diagnosing substance abuse, but changed to replace ‘substance’ with ‘food’, is as follows;

  • Cravings to use the food
  • Wanting to cut down or stop but not managing to
  • Taking the food in larger amounts or for longer than you meant to?
  • Neglecting other parts of your life because of food
  • Continuing to use it despite causing problems in your relationships?
  • Using food even when it puts you in danger?

Much of this comes back to the dopamine response – pleasure-seeking behaviour.


Now I’m pretty sure you’ve heard this one….

If you think you’re hungry… have a drink instead, because your brain confuses mild thirst with hunger.

Now when I was researching this video I wasn’t sure whether this was true scientific fact of those pieces of common wisdom that has just become obvious advice – because there are loads of those in the world of nutrition and weight loss.

You know… like breakfast is the most important meal of the day!

I couldn’t find anything to say this is true.

Now the absence of evidence doesn’t mean it isn’t true… so hey, if it works for you then great. But what I did find out was that hyper-processed foods weaken our thirst sensitivity…

Personally I’m much more aware of my thirst since cutting out the junk food and significantly cutting back on my carbohydrate intake.

Emotional Eating

Emotional eating is a huge problem for many people. Whether due to low mood, grief, distress. We use food for comfort and food for coping. Often this is a vicious cycle as overeating can lead to guilty feelings, which makes the original problem worse.

It’s really important that people get appropriate treatment for mood problems and also try to develop non-food-related coping mechanisms.


The relationship between stress and food very much varies between individuals. Mild stress can lead to increased food consumption and overeating, whereas extreme stress often leads to decreased food consumption and under-eating.
medical reasons for not losing weight

But when these people do eat they tend to go for hyper-palatable, quick hit types of foods.

There is a definite link between increased cortisol levels (stress hormone) and increased snacking.

Sleep Deprivation

It’s well known that if sleep goes down, weight goes up. When people are sleep deprived it is known that they have higher levels of the hormones that make us hungry. People make significantly worse decisions about food after a poor night’s sleep. This is particularly problematic for shift workers.


Cultural eating can take many forms . One thing I see commonly in say the workplace is …..Cake culture – oh it’s Susan’s birthday and she’s brought a load of doughnuts in… it would be rude not to.

Whilst there is no denying that there is often a lot of love and good intention behind this sentiment. But the larger your workplace, the more birthdays there are… which adds up to a lot of doughnuts over the year!

The Festive seasons tend to be times of increased cultural consumption. Certainly Christmas in the UK is a pretty glutinous time.

Some studies suggest that most weight gain happens around the Christmas period. There is a correlation between the number of events attended and the weight gained.

It seems that there is always something going on where we need to celebrate with food. Easter Eggs, Valentines day, Thanksgiving! These cultural events often have a history which originates back to religious feast days. However these used to be balanced with fast days, which seem to have long been forgotten in most of our modern cultures.


Can being overweight actually lead to overeating? Yes! There seem to be several reasons why this happens.

Firstly, we know that people who are overweight need to eat more for the same hit of dopamine.

Secondly, being overweight can often lead to negative feelings towards their body image, which can lead to low mood which can in turn lead to comfort eating.

But people with obesity often also have a hormonal condition called Insulin Resistance. In a nutshell that means they need more insulin to do the same amount of work than someone who is not insulin resistant.

If you’re obese, then you’ve got plenty of energy stored all over your body as fat but the elevated levels of insulin are keeping your body in storage mode so that you can’t easily access those energy stores and so you continue to feel hungry.

Dietary Guidelines

If you’re anywhere in the western world then it’s likely your national dietary guidelines will look something like this.

Eat plenty of whole grain carbohydrates, protein, and very little fat.

Now whilst a handful of people do seem to do pretty well on these guidelines most people don’t really follow them.

I always hear that the problem isn’t with the dietary guidelines, it’s that people don’t stick to it. But why can’t they stick to it? Because it’s an unsustainable diet that isn’t what humans are designed to eat.

Now firstly there is no evidence to support this way of eating. Particularly the low fat side of it. These dietary guidelines came out of political motivations in the 1970s.

Low fat diets for most people simply don’t work. The body needs fat. It is very filling. It’s an essential nutrient, unlike carbohydrates.

For overweight people who have established insulin resistance, continuing to consume a high carbohydrate diet is only going to make the problem worse.