Why Week 2 is so hard, and how cravings pass

Weekend Read · Week 2 · 11 min read · Reviewed against peer-reviewed evidence, October 2026

This week is meant to feel harder, and that tells you something useful

For many people, Week 2 is the toughest. The berries, honey, stevia and evening square of dark chocolate all go.

What you may discover is that sweet things were doing a job: the 3pm break, the reward for getting the kids to bed, the edge taken off a long day. Take the food away and the job is still there. What shows up in its place is a craving, and it behaves in very predictable ways.

A craving is a learned cue, not a character flaw

Psychologists describe cravings as learned responses. Your brain links a cue with a reward, and after enough repeats, the cue alone triggers the wanting. In a 2016 meta-analysis pooling 45 reports and more than 3,200 people, both cravings and reactions to food cues reliably predicted later eating (Boswell & Kober, 2016).

The surprising part: pictures and videos of food were about as powerful as real food, and stronger than food smells. The dessert reel you scroll past at 9pm counts as a cue.

Why it starts as a thought and becomes a craving

One influential theory, developed partly at the University of Queensland, splits a craving into two stages. First comes an intrusive thought, triggered automatically by a cue or by a feeling like tiredness. Then, if the thought is pleasant, we elaborate it: we picture the taste, the texture, where the biscuits are kept. That vivid mental picture turns a passing thought into a real pull (Kavanagh et al., 2005). So there are two places to step in: reduce the cues, and interrupt the picture.

Habits take longer than 21 days

In the study most often cited on this, volunteers chose a new daily habit and tracked it. The median time to reach near-automatic was 66 days, with a wide range of 18 to 254. Missing a single day made little difference (Lally et al., 2010). It's one study, but the message holds: the eight weeks matter more than any perfect day.

Is sugar addictive? The honest answer is "not in the way you've heard"

Headlines saying sugar lights up the brain like a drug mostly come from rat studies. When Cambridge researchers reviewed the evidence, they found little support for sugar addiction in humans. In animals, binge-like behaviour showed up mainly when sugar was offered on and off. The authors concluded it most likely comes from intermittent access to sweet, highly palatable food, not a drug-like effect of sugar itself (Westwater et al., 2016).

So we won't call sugar a drug. But your Wednesday afternoon craving is still real. It's what happens when a much-practised reward goes missing, and what was learned can be relearned.

Tired and stressed brains go looking for sweet things

Sleep

In a small but well-known trial, 12 healthy young men spent two days on restricted sleep and, on another occasion, two days with extended sleep. After the short-sleep days, the hormone that signals fullness (leptin) was 18% lower and the hormone that drives hunger (ghrelin) was 28% higher. Hunger rose by about a quarter, and appetite for energy-dense, carbohydrate-rich foods rose by 33 to 45% (Spiegel et al., 2004).

Brain imaging adds another layer. After a night without sleep, the frontal regions that weigh up food choices were quieter and the more reactive amygdala was busier. People wanted energy-dense foods more, and the more sleep-deprived they felt, the stronger the effect (Greer et al., 2013).

Both studies were small and in young adults. But the direction is consistent: a bad night makes the next day's cravings louder. That's biology, not a lack of resolve.

Stress

In a laboratory study of 59 pre-menopausal women, those whose cortisol rose most in response to a stressful task ate more after it than women with a smaller cortisol response, and they ate more sweet food overall (Epel et al., 2001). It's one study, but many women will recognise the hard day that ends with a hunt through the pantry. Our article on the cortisol and blood sugar loop explains how the two feed each other.

Headaches and grumpiness in the first days: what's actually going on

Some people feel flat, irritable or headachy early in Week 2. It's often called "sugar withdrawal", but that isn't established in humans. More likely explanations:

• Caffeine. If cola, energy drinks, chocolate or sweet iced coffees have dropped out of your days, your caffeine intake may have dropped too. Caffeine withdrawal is well documented: in experimental studies about half of people got a headache, typically starting 12 to 24 hours after stopping and lasting two to nine days, often with fatigue, irritability and fogginess (Juliano & Griffiths, 2004). Your coffee stays this week, so keep it steady.
• Not eating enough. Taking out fruit and snacks without adding anything back can simply leave you hungry, and hunger feels a lot like grumpiness.
• A big change in routine. New shopping, new cooking, new decisions. That's tiring in itself.

The fix is unglamorous: eat all your meals, add fat and protein, drink water. If headaches are severe, persistent or unusual for you, see your GP.

Why everything sweet comes out for a while, and what the taste research really says

Last week we mentioned a trial in which people who cut their sugar for three months rated the same puddings about 40% sweeter (Wise et al., 2016). It's a real finding, but the full picture is more mixed, and you deserve it.

In that trial, how much people liked sweetness didn't change. A 2018 systematic review found the evidence on whether eating less sweet food changes sweet preferences was small and inconsistent (Appleton et al., 2018). And the largest trial so far randomised 180 adults to low, regular or high sweet-taste diets for six months. There was no difference between groups in how much they liked sweetness or how sweet things tasted (Čad et al., 2025).

So we won't promise your taste buds will change. Here's why everything sweet still comes out this week.

• It breaks the loop cleanly. Every cue fires without the reward, rather than sometimes getting it.
• It removes the negotiation. "Just a couple of dates" is a decision you'd make ten times a day. "Not this week" is one decision.
• It makes Week 6 a choice. When berries come back, you add them deliberately, and many people notice they enjoy them more.

Cravings rise, peak and pass

A craving feels as though it will keep building until you give in. "Urge surfing", a technique from addiction psychology, treats it like a wave: you notice it build, peak and fall, without acting on it. In a trial of 123 student smokers, brief urge-surfing instructions didn't weaken the urge in the moment, but that group smoked fewer cigarettes over the following week (Bowen & Marlatt, 2009). It was smoking, not food, but the lesson carries: the aim isn't to make the craving vanish. It's to let it be there and not obey it.

Two small studies suggest ways to shorten the wave:

• Move. Regular chocolate eaters who'd gone three days without it took a 15-minute brisk walk or sat quietly. The walk reduced their urges to eat chocolate (Taylor & Oliver, 2009).
• Occupy your mind's eye. Because cravings run on mental pictures, a visual task competes with them. In one week-long study, three minutes of Tetris on a phone lowered everyday craving strength by about 14 points out of 100 (Skorka-Brown et al., 2015).

Your Week 2 craving plan

When a craving hits

• Ask: hungry or craving? Four hours since you ate? It's probably hunger. Have a snack built on fat and protein: a boiled egg, a handful of nuts, cheese with cucumber, plain full-fat yoghurt with toasted coconut, half an avocado with lemon and salt.
• Not hungry? Change state. A short walk, a stretch from your movement plan, or a peppermint, rooibos or ginger tea (skip fruit-flavoured blends this week).

Plan for 3pm

Eat a lunch with real protein and fat in it, and keep a snack from your meal plan within reach so you're not choosing on an empty tank. Use your Sunday cook-up to boil eggs and roast a batch of spiced nuts or coconut chips. Pair the snack with a 10-minute walk if you can.

Plan for after dinner

The after-dinner sweet is usually pure habit: the meal ends, so dessert begins. Keep the ritual and change what's in it: herbal tea in a favourite cup, warm milk with cinnamon, or a few macadamias. Then close the kitchen for the night.

Protect your sleep this week

Given what sleep loss does to appetite, an earlier night may be your most useful craving tool. Try being in bed half an hour earlier this week, with screens parked.

The evidence map

A snapshot of the studies behind this article. "Strong" means a systematic review or meta-analysis with a consistent result. "Moderate" means good-quality individual studies. "Emerging" means early or small studies.

Theme	Study	Strength	Finding
Cues and cravings	Boswell & Kober, 2016	Strong	Cravings and cue reactions predicted later eating; pictures worked as well as real food.
Sugar addiction	Westwater et al., 2016	Moderate	Little evidence for sugar addiction in humans; animal bingeing tied to intermittent access.
Habit formation	Lally et al., 2010	Emerging	Median 66 days to near-automatic (range 18–254); one missed day made little difference.
Sleep and appetite hormones	Spiegel et al., 2004	Emerging	Short sleep lowered leptin, raised ghrelin and increased appetite for carbohydrate-rich foods.
Sleep and food desire	Greer et al., 2013	Emerging	Sleep loss increased desire for energy-dense foods.
Stress and sweet food	Epel et al., 2001	Emerging	Women with a bigger cortisol response ate more after stress, and more sweet food.
Caffeine withdrawal	Juliano & Griffiths, 2004	Strong	Review of 66 studies: headache in about half; symptoms last 2–9 days.
Taste reset	Wise et al., 2016; Appleton et al., 2018; Čad et al., 2025	Moderate	Mixed: sweetness tasted stronger in one trial; a review and a larger trial found little or no change in sweet liking.
Urge surfing	Bowen & Marlatt, 2009	Emerging	Same urges, but less smoking over the next week.
Walking and cravings	Taylor & Oliver, 2009	Emerging	A 15-minute brisk walk reduced urges to eat chocolate.
Visual distraction	Skorka-Brown et al., 2015	Emerging	Three minutes of Tetris lowered craving strength.

If you're in perimenopause or menopause

The menopausal transition is linked with more insomnia symptoms, especially waking in the night, and hot flushes and night sweats are a key part of that (Baker et al., 2018). Put that next to what short sleep does to appetite, and it's no surprise many women find cravings stronger in midlife. It isn't a failing.

So the sleep part of this week's plan matters even more: a cooler bedroom, a steady bedtime, the after-dinner wind-down. If night waking or sweats are wrecking your sleep, raise it with your GP. The same review notes hormone therapy can ease sleep problems, particularly when hot flushes are involved, and there are other options if it isn't right for you.

What this article isn't saying

• That fruit is unhealthy. It isn't. It's out for a few weeks to break a habit, and it comes back in Week 6.
• That sugar is a drug or that you're "addicted". The human evidence doesn't support that.
• That your taste buds will definitely change. The research is mixed, and we'd rather tell you that.
• That a craving you act on means you've failed. One slip doesn't undo a habit.

Common questions

Why can't I have berries? They're low in sugar.

They are, and they're among the first things back in Week 6, along with a little stevia or rice malt syrup. This week isn't about the sugar in any one food. It's a clean break for the sweet-reward loop, and that works best with a simple rule: nothing sweet, for now.

I gave in on Tuesday night. Have I undone everything?

No. In the habit study above, missing a single day made little difference (Lally et al., 2010). Notice the cue, plan for it, and pick up at your next meal. No compensating, no skipping breakfast.

I have diabetes. Anything to watch this week?

This is a bigger change than Week 1. If you take insulin or medication that lowers blood sugar, check with your GP or diabetes educator first, keep monitoring as usual, and keep your hypo treatment with you. Treating a low is medical care, not a slip.

If cravings ever feel out of control, or you find yourself eating in secret or feeling real distress around food, a meal plan isn't the right tool. Talk to your GP or a dietitian, or call the Butterfly Foundation on 1800 33 4673. It's free and confidential.

About this article

Written by the I Quit Sugar team for the 8-Week Program, and reviewed against the peer-reviewed sources listed below.

Not medical advice. This article is general education. It isn't a diagnosis or a substitute for advice from your own health professional. If you're managing a medical condition, are pregnant or breastfeeding, or take medication, speak with your doctor before making significant changes to how you eat.

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