If you want better energy, fewer crashes, and a calmer gut think ‘food first’. Focus on adding in the good rather than denying yourself the bad. When you get more good foods in, the unhelpful ones get crowded out.
Why food comes first
In functional medicine we talk about the exposome: the total of your daily inputs, or things your body is exposed to. Food is the biggest, most repeatable input you control. Your meals act like messages. They influence hormones, immune tone, mitochondria, and the microbes in your gut and can even control which genes are expressed. Change the inputs and you change the signals your body reads. I want to help you move towards steadier energy, lower inflammation, and better digestion by gradually building in the right variety of nutritious whole foods, step by step.
The Core Food Plan, in plain English
On the AFMCP course from the Institute for Functional Medicine which I recently completed we learnt about the ‘Core Food Plan’ and I think it contains simple but powerful principles that can transform people’s health. This is the IFM starting point. It’s not a diet with rules. It’s a simple way to build meals that actually help you feel better. Here are some of the key points:
- Make half your plate non-starchy vegetables. Raw and cooked both count.
- Include protein at every meal: fish, eggs, poultry, tofu or tempeh, beans and lentils.
- Use healthy fats: extra-virgin olive oil, avocado, nuts, seeds, and oily fish.
- Choose smart carbs rich in fibre: whole fruit, legumes, and gluten-free whole grains if tolerated (quinoa, buckwheat, brown rice).
- Cook at home more than you buy restaurants. Repeat simple meals you enjoy.
- Aim for diversity. Try to get a range of vegetables and fruits of different colours each day and across the week. See more in the ‘Eat the Rainbow’ section below.
And the golden rule: just add the good stuff. Don’t open with denial and trying to restrict yourself. Focus on adding delicious whole foods like berries, vegetables, nuts and fruit to your diet. For example add two small handfuls of mixed nuts and seeds across the day. Swap them in for crisps or other starchy snacks. Add a side salad with olive oil. Add frozen berries to breakfast. Over a few weeks, these additions quietly displace the less helpful foods.
Phytonutrients 101: food as instruction
Plants are rich in natural compounds called phytonutrients, from the pigments that colour berries to the bitter notes in leafy greens. These act as signals, not just fuel, helping to tune gene activity, strengthen your own antioxidant defences, support healthy blood vessels, and feed the microbes in your gut. Eat colour and you send your cells clear instructions. If you’re interested in the science check out this excellent overview of phytonutrient families and health effects click here, or check out my previous article on exposome vs genome here.
Here are just a few examples of the powerful phytonutrients found in some common foods:
- Sulforaphane from broccoli and especially broccoli sprouts. It switches on a master pathway called Nrf2, which raises your own antioxidant and detox enzymes. That’s inside-out defence, not just topping up with a pill. (MDPI)
- Anthocyanins from blueberries, blackberries, purple cabbage, and aubergine skins. These pigments support the lining of your blood vessels and appear to help brain signalling and memory markers in human studies. (PMC)
- Allicin and prebiotic fibres from onions, garlic, and leeks. They feed helpful gut microbes, which produce short-chain fatty acids that calm inflammation and support the gut barrier. (PMC)
Eat the Rainbow: the simplest way to start
Different colours signal different families of phytonutrients. Aim for five colours a day and about 30 plant varieties a week. You can start with common varieties of vegetables and fruit that you are familiar with, and then, if you like, you can branch out and try new things. Diversity and consistency beats perfection. (The “30-plants” target comes from large microbiome datasets showing higher microbe diversity in people who hit it see here: PMC)
Red (think lycopene and friends)
Tomatoes and passata, red peppers, strawberries, watermelon, pink grapefruit. Easy wins: tomato salad with olive oil; sliced peppers with hummus.
Orange (beta-carotene)
Carrots, butternut squash, orange peppers, apricots. Easy wins: roast carrot and squash tray; grated carrot in a salad.
Yellow (lutein and zeaxanthin)
Yellow peppers, sweetcorn, yellow courgettes, lemons. Easy wins: corn and black-bean salsa; lemon zest and juice over greens.
Green (folate, magnesium, sulforaphane)
Broccoli, kale, cabbage, rocket, spinach, peas, fresh herbs. Easy wins: steamed greens with olive oil; broccoli stir-fry; herb-heavy salads.
Blue/Purple (anthocyanins)
Blueberries, blackberries, blackcurrants, aubergine, purple cabbage. Easy wins: berries on yoghurt or kefir; quick slaw with purple cabbage.
White/Tan (allicin, prebiotic fibres)
Onions, garlic, leeks, mushrooms, cauliflower, ginger, oats. Easy wins: mushroom and leek omelette; cauliflower rice under a stir-fry.
Your gut will thank you
More colours mean more prebiotic fibres and polyphenols. These feed a wider range of microbes, which is linked with better gut resilience, decreased inflammation and a whole host of health benefits. Evidence shows that people who eat 30+ different plants each week show greater microbiome diversity than those who eat fewer. Practically, that often translates to steadier bowels, a calmer belly, and fewer post-meal slumps. (PMC)
Put it into action this week
Keep this simple. Start by adding, not banning.
- Shop one new food from each colour that you’ll actually eat. Put them on this week’s list.
- Add two servings of mixed nuts and seeds daily. Use them to replace crisps (potato chips for our American friends!) and biscuits (cookies!). A small handful mid-afternoon and another after dinner works well.
- Batch one tray of mixed veg for easy sides. Toss in olive oil and salt. Roast once, eat three times.
- Choose one default meal you’ll repeat on busy days. Two ideas:
- A big salad (half veg) + protein + olive oil and lemon.
- A veg-loaded omelette with a side of berries or a simple green salad.
When you’re used to these, add another plant or two into your regular rotation. Keep going until your shop and your plate look more colourful without much thought.
Tiny next step: add blueberries, rocket, mixed peppers, garlic, and a nut–seed mix to your basket today.
Troubleshooting and personalisation
If a fibre jump makes you gassy, increase slowly and cook veg well. Add fermented foods like kefir or live yoghurt if tolerated, and drink enough water (8-12 glasses per day / 2-3l). If you’re gluten-free, focus on whole-food swaps rather than ultra-processed “GF” treats. If you have kidney issues or take medicines like warfarin, check with your clinician before making dramatic changes to your diet.
Track what matters
Repeat the Symptom Self-Check in 2–4 weeks. Note your rainbow score (colours per day, plants per week). Watch your energy curve and bowels. Aim for one to two formed movements a day. Adjust as you learn what works.
Evidence snapshot
- IFM Core Food Plan — practical framework for building meals that support energy, inflammation, and gut health. (Healing Unleashed)
- Phytonutrient diversity — human-focused reviews linking plant bioactives to metabolic, vascular, and immune benefits. (PMC)
- Sulforaphane → Nrf2 — raises cellular antioxidant and detox defences. (MDPI)
- Anthocyanins — associated with improved endothelial function and cognition markers. (PMC)
- 30 plants/week and the microbiome — greater plant variety correlates with higher gut microbe diversity. (PMC)
Subscribe to the Sunday Reset for one clear plan each week.
Disclaimer: Education only, not medical advice. Speak to your clinician before making changes, especially if you take medication or have a diagnosed condition.
