Dr Libby: Why is your 3pm sugar craving suddenly worse? Blame January ...
Why you might be feeling irritable, anxious and craving sweet treats after the holidays.
Blood sugar is not something to fear or fixate on. It is simply part of the mechanism your body uses to deliver energy to your cells. When it is well regulated, energy feels reliable. When it is not, energy can feel borrowed – there one moment, gone the next.
Insulin is the hormone that makes this delivery possible. Each time you eat, insulin helps usher glucose out of the bloodstream and into your cells, where it can be used for energy, repair and also stored as fuel for later. When this process runs smoothly, the body feels calm and steady. When it doesn’t, energy, mood and resilience become less predictable.
A sharp rise in blood glucose requires a surge of insulin to bring it back down. On the other hand, plummeting blood glucose can require different hormones to top up levels, as we can pull stored glucose (known as glycogen) out of storage. These hormones include glucagon and adrenaline, the latter being one of our stress hormones. This is why low blood sugar can feel like irritability, anxiety or an urgent need for something sweet. It is not a failure of discipline. It is physiology asking for reassurance.
January offers a natural pause point to restore balance. After weeks of irregular meals, richer foods, alcohol and disrupted sleep, both blood sugar regulation and insulin sensitivity can lose their usual rhythm. When that happens, the body has to work harder to keep energy available, and the cost of that effort is often felt as fatigue, cravings and emotional dips. This does not call for restriction or rules, just a return to steadiness.
One of the most supportive shifts is to eat in a way that signals safety to the body – that energy is coming regularly and reliably. Meals that include good-quality protein, fibre and nourishing fats slow down digestion and soften blood sugar peaks, which in turn allows insulin to respond more smoothly. Over time, this supports steadier energy and a calmer metabolism. It does not mean January needs to feel austere. Summer food can still be pleasurable while feeling grounding, rather than fleeting.
Think grilled fish with steamed vegetables, avocado and olive oil. Salads that include meat, lentils, kumara and/or quinoa (doused in olive oil), so they sustain you for longer. These are small adjustments, yet they meaningfully change how the body experiences food.
Breakfast often sets the tone for the day. Starting with something sweet on an empty stomach can trigger a quick rise and fall in blood sugar, particularly when paired with coffee. A savoury breakfast, or simply adding protein to what you already enjoy, can make mornings feel calmer and more focused. Even something gently sweet, like chia pudding made with coconut milk, can provide a slower, steadier release of energy.
Lunches built largely around refined carbohydrates without enough protein or fats often explain the mid-afternoon slump that so many people accept as normal. It is not inevitable. It is informative. When insulin is repeatedly asked to work hard without enough nutritional support, energy delivery becomes inconsistent. Snacks take on a different role when blood sugar is steadier. Instead of acting as an emergency response, they become optional support.
Pairing whole food carbohydrates with protein or nourishing fats helps insulin do its job without urgency.
Alcohol deserves a mention too. While it may feel relaxing in the moment, it can destabilise blood sugar and disrupt sleep. As the liver prioritises processing alcohol, blood sugar can dip, triggering stress hormones that contribute to early waking and morning fatigue.
Yet what we eat is only part of the story. How we eat matters just as much. Meals eaten quickly or while scrolling tend to bypass the body’s early digestive signals. Digestion begins in the brain. When you see, smell and anticipate food, the body prepares enzymes and hormones that help manage blood sugar efficiently. When meals are rushed or distracted, those signals arrive late. Slowing down changes this dynamic. Sitting down, avoiding screens, chewing thoroughly and giving a meal your attention allows the body to register nourishment. Blood sugar rises more gently, insulin responds more smoothly and satiation signals come sooner. If you’re someone who scoffs down your food, try putting your knife and fork down between each bite to help you slow down a little.
We also cannot talk about blood sugar without acknowledging stress. Elevated stress hormones raise blood sugar by design, ensuring fuel is available for perceived demands. Insulin then has to respond, even when that rise was not driven by food. In December, stress often runs quietly alongside celebration. For many people, it lingers into January. Creating calmer mornings, eating before caffeine and allowing more space around meals all help to reduce your stress hormone production. When that happens, blood sugar regulation follows.
A January reset is not about undoing December or punishing the body for celebration. It is about restoring equilibrium. Offering predictability, nourishment and enough safety to stop your body shouting at you for fuel. When blood sugar and insulin are working together, life feels easier. Energy becomes reliable rather than borrowed. Moods are steadier. Decisions feel clearer. January does not need to be about transformation. Sometimes it is simply a return to rhythm – and that is often exactly what the body has been asking for.
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