The Truth About Cravings: Biological, Emotional and Habit-Based Causes

Cravings are one of the most misunderstood parts of eating behaviour. Many people see them as a lack of willpower, but that is not accurate. Cravings are biologically driven, psychologically reinforced, and shaped by our habits and environment.

Understanding the root of cravings is the first step to managing them without guilt, shame, or overly restrictive dieting. Here is what the science tells us.

1. Biological Causes of Cravings

Cravings often begin at the level of chemistry, hormones, and the brain. They are not a personal failure. They are a physiological signal.

1.1 Blood Sugar Fluctuations

When blood glucose drops too low (hypoglycaemia), the body sends urgent signals to push you towards quick-energy foods.This is why sugary or high-carbohydrate foods are especially appealing when:

• You have not eaten for several hours

• Meals are unbalanced (low protein, low fibre)

• You have had poor sleep

• You are stressed

Low blood sugar increases ghrelin, the hunger hormone, and reduces leptin, which normally helps you feel satisfied. This hormone mix drives stronger, more urgent cravings.

UK relevance: Many people eating a typical Western diet with long gaps between meals or skipping breakfast report stronger afternoon or evening cravings due to unstable blood sugar.

1.2 Hormonal Changes

Hormones heavily influence food preferences and intensity of cravings.

Menstrual cycle

In the luteal phase (after ovulation), fluctuations in oestrogen and progesterone can:

• Increase appetite

• Reduce insulin sensitivity

• Increase metabolic rate

• Increase cravings for carbohydrate-rich foods

This makes cravings around menstruation completely normal.

Stress and cortisol

When stressed, the body releases cortisol, which increases desire for energy-dense foods (often those high in fat, sugar, or both). These foods trigger dopamine release, creating a short-term sense of relief.

Poor sleep

Just one night of poor sleep affects appetite hormones:

• Ghrelin ↑ (more hunger)

• Leptin ↓ (less satisfaction)

This imbalance drives cravings for high-reward foods the next day.

1.3 Brain Reward Pathways

Cravings are partly driven by the dopamine reward system. Foods high in sugar, fat and salt activate the brain’s reward centre more strongly.

Over time, repeated exposure can create a stronger “reward memory”:

Your brain remembers the food, remembers the relief, and prompts you to seek it again.

This does not mean food is “addictive” in the same way as substances, but it does mean the brain can become conditioned to expect pleasure from certain foods.

1.4 Nutrient Deficiencies (sometimes)

Although often overstated online, certain deficiencies can contribute to cravings:

• Low iron can increase desire for ice (known as pica)

• Low magnesium may influence chocolate cravings (though evidence is mixed)

• Low protein intake often increases general hunger and cravings

These issues should be addressed with a GP or dietitian if suspected.

2. Emotional Causes of Cravings

Food is deeply linked to emotion, comfort, and coping mechanisms. Cravings triggered by feelings, are extremely common.

2.1 Stress, Anxiety and Overwhelm

Stress cravings stem from:

• Cortisol signalling the body to seek quick energy

• A desire for emotional relief

• Learned coping patterns (“I feel stressed → I snack → I feel better temporarily”)

This loop is powerful, but with awareness it can be reshaped.

2.2 Comfort and Soothing Needs

When you crave “comfort foods”, your body may actually be seeking:

• Warmth

• Emotional safety

• Nostalgia

• Predictability

• Relief from loneliness or sadness

Food becomes a substitute for comfort when other coping tools are less available.

2.3 Reward and Celebration

In the UK especially, food is a major part of social reward:

• “Treating yourself” after a long week

• Tea + biscuits as a break

• Using sweets to reward children (which can shape lifelong patterns)

These patterns become emotionally reinforced and automatic.

2.4 Boredom Eating

Boredom is one of the most overlooked emotional triggers.Eating produces dopamine, which temporarily fills the “stimulation gap”.This is why cravings often happen in the evening, when mental stimulation is lower.

3. Habit-Based Causes of Cravings

Not all cravings are emotional or biological. Some are simply the result of learned routines and environmental cues.

3.1 Conditioned Eating Patterns

Example:If you always have something sweet after dinner, your brain begins to expect it.Over time, this becomes a habit loop:

• Cue: finish dinner

• Routine: get dessert

• Reward: pleasure + dopamine

You may not even be hungry; your brain is following a script.

3.2 Environmental Cues

Cravings can be triggered just by:

• Seeing food on TV

• Walking past a bakery

• Smelling fresh bread

• Having snacks visible in your kitchen

• Opening the fridge “just to look”

These environmental cues activate the brain’s reward system.

3.3 Under-eating or Over-restriction

Dieting behaviours, especially highly restrictive or “all-or-nothing” approaches, often lead to rebound cravings.When you heavily restrict a food:

• It becomes more psychologically desirable

• You think about it more

• You may end up bingeing later

This is a well-documented pattern in behaviour-change research and eating-psychology studies.

3.4 Irregular Eating Patterns

Skipping meals or long gaps between eating increases biological drive for high-reward foods later.This is why many people find evenings the hardest time. It is often the end of a long gap, combined with fatigue and emotional load.

4. How to Identify Your Type of Craving

A craving can fall into more than one category. Try asking:

• Is this physical hunger?

Look for: stomach rumbling, low energy, irritability, difficulty concentrating.

• What was I feeling just before the craving?

Stress? Boredom? Loneliness? Reward-seeking?

• Is this a time-triggered craving?

Always around 8pm? Always mid-afternoon?

• Did something cue this?

A smell, sight, or routine?

• Would any food satisfy me, or only one specific food?

Specific-food cravings often signal emotional or reward-based triggers.

5. The Takeaway: Cravings Are not the Enemy — They are Information

Cravings are not a flaw or lack of discipline.They are a message from your body, mind, or habits.

Understanding the why behind cravings helps you respond with:

• More self-awareness

• Better tools

• Less guilt

• More sustainable change

And ultimately, that leads to healthier eating patterns and a better relationship with food.