As the clocks go back and daylight fades, it’s common to feel a dip in motivation, energy and even mood. For active people, that “autumn slump” can hit hard — training feels tougher, recovery slower, and colds seem to lurk around every corner. But your nutrition can be a powerful ally in keeping energy levels high, immunity strong, and motivation ticking through the darker months.
Here’s how to eat smart this autumn to stay energised, recover well, and head into winter feeling your best.
1. Understand What’s Behind the Autumn Slump
The drop in energy at this time of year isn’t just in your head. Shorter days mean less sunlight exposure, which can lower vitamin D levels and affect mood-regulating hormones like serotonin and melatonin. Cooler temperatures and increased time indoors make it easier for viruses to spread, while comfort food cravings and less fresh produce can leave your diet a bit less colourful (and less nutrient-dense) than in summer.
Combine that with the fact that many athletes are in heavier training blocks or ramping up off-season base work, and you’ve got a recipe for fatigue if nutrition slips. So rather than fighting the slump, work with your body’s needs and adjust your nutrition to support the season.
Sunlight is the best source of Vitamin D but, with shorter days, it can't be relied upon
2. Prioritise Immune-Boosting Nutrients
Your immune system runs on more than just vitamin C — though that’s still important! Focus on a broad spectrum of nutrients that all play key roles in keeping defences strong.
• Vitamin D:
In the UK, it’s almost impossible to get enough vitamin D from sunlight between October and March. Low levels are linked with fatigue, poor recovery, and increased susceptibility to infection. The NHS recommends adults take a daily supplement of 10µg (400 IU) of vitamin D through winter months.
Food sources include oily fish (salmon, mackerel, sardines), egg yolks, and fortified foods, but a supplement is the most reliable way to maintain healthy levels.
• Vitamin C and Zinc:
These two nutrients work hand in hand to support immune cell function and tissue repair.
Find them in colourful fruits and vegetables — think peppers, kiwis, citrus, berries, broccoli — and in nuts, seeds, and lean meats.
• Iron:
Low iron can leave you feeling flat and fatigued, particularly if you train hard or follow a mostly plant-based diet.
Red meat, lentils, tofu, and leafy greens are all great sources. Pair plant sources with vitamin C-rich foods to boost absorption.
• Omega-3 fatty acids:
Known for their anti-inflammatory benefits, omega-3s support immune balance and recovery.
Oily fish is best, but walnuts, flaxseed, and chia seeds are good plant-based alternatives.
3. Keep Energy Levels Stable with Smarter Carbs
Oats are a staple in our household throughout winter
When it’s darker and colder, cravings for quick comfort carbs often skyrocket — but relying on refined carbs and sugary snacks can send your blood sugar on a rollercoaster, leaving you sluggish later in the day.
Instead, focus on slow-release carbohydrates that provide steady energy and help regulate appetite and mood:
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Oats, quinoa, wholegrain rice and pasta
Sweet potatoes and root vegetables
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Beans, lentils, and chickpeas
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Whole fruits instead of juices
Try combining these with protein and healthy fats in every meal — for example, overnight oats with yoghurt and berries for breakfast, or roasted sweet potato with salmon and greens for dinner. This balances your blood sugar and keeps you fuller for longer.
4. Don’t Neglect Protein
You might not be training for your A-race right now, but protein remains crucial for maintaining lean muscle mass, supporting recovery, and helping your immune system produce antibodies.
Aim for 1.6–2.0g of protein per kilogram of bodyweight daily, spaced evenly across meals and snacks.
Good sources include chicken, fish, eggs, Greek yoghurt, tofu, beans, lentils, and whey or plant-based protein powders.
Yoghurt is a great high-protein snack to enjoy mid-afternoon
For those struggling to hit their targets, a protein-rich snack between meals — like cottage cheese with fruit, or hummus with oatcakes — can make a big difference.
5. Support Gut Health (and Your Immune System)
About 70% of your immune system resides in your gut, so nurturing a healthy gut microbiome is one of the best ways to stay well through winter.
Focus on variety and fibre — the more different plant foods you eat each week, the more diverse your gut bacteria will be. Aim for at least 30 different plant-based foods per week, including fruits, vegetables, nuts, seeds, grains, herbs, and spices.
You can also incorporate fermented foods like kefir, yoghurt, sauerkraut, kimchi, and kombucha to support healthy gut flora.
6. Hydrate — Even When You Don’t Feel Thirsty
It’s easy to forget about hydration when it’s cold outside and you’re not sweating as much, but dehydration can sap your energy, slow digestion, and weaken your immune response.
Use these quick checks to stay on top of hydration:
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Your urine should be pale yellow (not clear, not dark)
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You should be drinking consistently throughout the day, not just before or after training
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Herbal teas, soups, and water-rich foods like fruit and veg all count towards fluid intake
For most athletes, 2–3 litres of fluid per day is a good starting point, more if you’re still training hard.
7. Eat with the Season
The best way to eat carrots? Drizzled in honey and roasted in the oven!
One easy way to improve your nutrition this time of year is to eat seasonally. Autumn and winter bring naturally nutrient-dense foods perfect for energy and immune support:
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Root vegetables (carrots, parsnips, beetroot, sweet potatoes) — rich in complex carbs and antioxidants
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Brassicas (broccoli, kale, Brussels sprouts, cauliflower) — loaded with vitamin C and fibre
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Squash and pumpkins — excellent sources of beta-carotene and slow-release energy
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Apples and pears — great for snacking and packed with polyphenols
Seasonal eating isn’t just more sustainable; it’s also cheaper, fresher, and tastier.
8. Practical Tips to Stay Consistent
It’s not just what you eat — it’s how you set yourself up for success.
Here are a few small habits that make a big difference:
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Batch cook soups, stews, and grain bowls to have ready-made meals for busy weeks
Prep snacks like energy balls or roasted chickpeas to avoid the 3 p.m. slump.
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Eat the rainbow — the more colours on your plate, the broader the nutrient range.
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Plan around training: Fuel properly before and after workouts even if your sessions are indoors or shorter during winter.
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Supplement smartly: A daily vitamin D supplement is essential; omega-3s and probiotics can be worth considering if your diet lacks those foods.
High in protein and omega-3s, salmon is a great winter dinner
9. When to Seek Extra Support
If you find yourself constantly tired, run down, or catching every cold going, it’s worth checking in with a GP or sports nutritionist. Blood tests can identify low iron, vitamin D, or B12 — all common in active people, especially through winter.
The Takeaway
The autumn slump doesn’t have to derail your training or wellbeing. By focusing on steady energy, immune-supporting nutrients, and good hydration, you can power through the darker months feeling strong and resilient. Think of your nutrition as your secret weapon — fuelling your body not just for performance, but for everyday vitality.
