If you're aiming for a restful night, you likely know the golden rules: a dark room, no screens, and steering clear of caffeine. But experts are now highlighting a specific, and perhaps surprising, dietary culprit that could be undermining your slumber – and it has a strict afternoon cut-off time.
The 3pm Chocolate Deadline
According to Frances Ralph, an HCPC-registered dietitian specialising in gut health, the ideal time to stop consuming chocolate is by 3pm. Frances, who works with CityDietitians, advises that enjoying it even earlier is preferable to avoid a disrupted night.
"You might think a square or two of dark chocolate after dinner is a healthy indulgence – full of antioxidants," she explains. "But this treat can quietly sabotage your sleep."
Hidden Stimulants in Your Treat
The issue extends beyond just caffeine. Dark chocolate also contains theobromine, a lesser-known stimulant that can keep your heart rate slightly elevated and your mind more alert. The effects of this compound are surprisingly long-lasting.
One ounce (around 23g) of dark chocolate can deliver caffeine comparable to a small cup of green tea. More notably, theobromine can linger in your system for six to eight hours. This means an evening treat could still be stimulating your nervous system long after you've gone to bed.
"If you love chocolate, enjoy it earlier in the day, ideally before 3pm, when your body can metabolize those stimulants without affecting your sleep cycle," Frances recommends. She adds that this timing can also help combat the common mid-afternoon energy slump.
Better Bedtime Snacks and Foods to Avoid
For those craving a pre-bed snack, the dietitian suggests opting for more "sleep-supportive" options. A good example is a banana with almond butter, which provides magnesium and tryptophan. "While there is little research on individual foods that support good sleep, these foods are more likely to help your body wind down," she notes.
Frances also points out other unexpected sleep disruptors commonly seen in her clinic:
- Tomato-based sauces: Can trigger acid reflux.
- Aged cheese and cured meats: High in tyramine, a compound that stimulates alertness.
Her general evening advice is clear: "Aim to finish large meals at least three hours before bed, keep evening snacks light, and watch for hidden stimulants."
This guidance is echoed by Rebekah Parr, a health and wellbeing physiologist for Nuffield Health. She warns that high-protein meals, like those featuring steak or large chicken servings, should not be eaten too late as they take longer to digest. This extensive digestion uses energy and can limit the availability of tryptophan, a key component for producing the sleep hormone melatonin.
For an optimal evening meal, she recommends a balanced plate consumed two to three hours before bed, such as salmon, vegetables, and a small portion of sweet potato.
This article was first reported on October 30, 2025.
