Flat illustration of a smiling woman walking beside an Eatwell plate, fruits, vegetables, and a glass of water, representing eating well during cancer treatment and recovery.

Nutrition, Cancer, and My Body: What I Learned Before, During, and After My Diagnosis

ByAbigail Longley

First published at the Nutritional Harmony Blog (https://nutritionalharmony.blog), the companion site to our main platform at https://nutritionalharmony.co.uk.

Introduction

In October 2023, I was diagnosed with bowel cancer. What followed was a journey of understanding how my body responded to food, stress, and healing — and how eating well during cancer treatment and recovery became essential for supporting my gut, energy, and overall wellbeing.

By that point, I had already spent most of my adult life managing food-related symptoms: bloating, diarrhoea, migraines, dry flaky skin, and psoriasis flare-ups. These long-standing issues were linked to allergies, intolerances, and IBS-type reactions — not cancer.
(You can read more about this on my About page.)

Clinically, they believe the cancer itself developed only in the 2–3 years before my diagnosis. But because digestive symptoms were already so familiar, it was incredibly difficult to recognise when something new — and far more serious — was happening beneath the surface.

After my diagnosis, I received an electronic leaflet about diet and exercise. While helpful, it was very generic — and it didn’t take my allergies, intolerances, or sensory needs into account. At the time I didn’t yet know I was neurodivergent; I only knew I was struggling with severe anxiety and depression, which made following broad, one-size-fits-all advice even harder.

Lifestyle Foundations for Eating Well During Cancer Treatment, Recovery, and and Reducing Future Risk

Move Regularly

Adults should aim for 150 minutes of moderate activity (or 75 minutes of vigorous activity) each week, plus muscle-strengthening activities on two or more days. Breaking up long periods of sitting is equally important.
➡️ NHS Guidelines: https://www.nhs.uk/live-well/exercise/physical-activity-guidelines-for-adults-aged-19-to-64/

Movement plays a particularly important role in bowel cancer:

  • It supports gut motility, helping food move smoothly through the intestines.
  • Prevents stool from sitting too long in one place — reducing irritation, inflammation, and exposure of the intestinal lining to potential carcinogens.
  • Helps regulate digestion, weight, inflammation, and long-term bowel health.

Research shows:

  • Regular physical activity is associated with a 19% lower risk of colon cancer (National Cancer Institute).
  • Large meta-analyses show a strong inverse relationship between activity and bowel cancer risk.
  • Genetic research (Mendelian randomisation) suggests increased physical activity likely causally reduces colorectal cancer risk.

In simple terms:
Moving your body helps keep your gut healthy, reduces inflammation, and lowers long-term cancer risk.

Eat a Balanced, Varied Diet

Understanding what eating well during cancer treatment and recovery looks like can help you support your body’s healing. The Eatwell Guide recommendations apply here:

  • fresh fruit and vegetables,
  • wholegrains and fibre,
  • lean protein sources,
  • healthy fats,
  • hydration.

Five portions a day

“Eating the rainbow” ensures a wide range of nutrients, antioxidants, and plant compounds that support immune health and tissue repair.

Hydration

Staying hydrated supports digestion, fatigue management, and overall cellular function. Sugary drinks are best limited.

Reduce red and processed meats

High intakes are associated with increased bowel cancer risk. Reducing processed meats, and limiting saturated fat and added sugar, can support long-term gut health.

Nutrition When You Have Cancer

Supporting Strength and Energy

Cancer treatment places extra demands on the body. Eating well helps maintain strength, stabilise energy levels, and support tissue repair.

Managing Side Effects

Treatment can affect appetite, digestion, taste, and nutrient absorption. Flexible, personalised strategies often work better than strict diet rules.

Accessing Specialist Support

Oncology dietitian support is typically prioritised for patients undergoing long-term or intensive treatment.
For shorter treatment periods like mine, this support isn’t always offered — even though allergies, intolerances, IBS-type symptoms, or sensory sensitivities can make generic advice difficult to follow.

When available, specialist dietitians provide personalised guidance that leaflets simply can’t match.

Why Eating Well During Cancer Treatment & Recovery Matters

Eating in a way that supports your body is essential. Our mind and body are deeply connected, and both need a holistic approach during cancer treatment and recovery. Research shows that stress, depression, and anxiety can suppress the immune system — and when your emotional resilience is low, your physical resilience often follows.

Here’s why good nutrition makes a meaningful difference during and after treatment:

  • Helps you feel better emotionally, mentally, and physically
    (This could be a whole series — nutrition and mood is a huge topic.)
  • Provides the vital nutrients your body needs
    Vitamins, minerals, antioxidants, fibre, and protein all support healing and repair.
  • Supports energy, strength, and stamina
    Balanced nutrition helps stabilise fatigue and maintain muscle mass.
  • Promotes faster healing and recovery
    Nutrients like protein, zinc, vitamin C, folate, and omega-3 fats play key roles.
  • Keeps your immune system functioning as well as it can
    A nourished body is better able to respond to inflammation and infection.
  • Provides compounds that support long-term cell health
    Plant foods, fibre, polyphenols, and antioxidants help reduce inflammation.
  • Helps your body cope with treatment and side effects
    Good nutrition supports digestion, stabilises blood sugar, and reduces unintentional weight loss.
  • Helps maintain a healthy weight
    Whether preventing weight loss or managing gain, balanced eating supports stability.
  • Supports mood and mental health
    Nutrition influences the gut microbiome, inflammation, and neurotransmitters — all affecting mood and resilience.

For many people, eating well during cancer treatment and recovery isn’t about perfection — it’s about nourishment, stability, and supporting the immune system.

We all have hard days – take a look at my post on Low-Energy Cooking

Science Explainer Box: Why You Drink a Carbohydrate Drink Before Surgery

Pre-operative carbohydrate drinks

These are part of Enhanced Recovery After Surgery (ERAS) protocols, especially for bowel cancer. They are not “just sugary drinks.” They have a specific physiological purpose.

🔍 Why fasting alone isn’t ideal

Traditional fasting leads to:

  • increased insulin resistance,
  • muscle breakdown,
  • higher metabolic stress,
  • slower recovery,
  • increased discomfort.

💡 What the carbohydrate drink does

Drinking a clear carbohydrate drink 2–3 hours before surgery:

  • reduces post-surgical insulin resistance,
  • tops up glycogen stores,
  • reduces muscle breakdown,
  • supports healing and recovery,
  • improves comfort.

Research

ERAS studies show:

  • improved insulin sensitivity,
  • reduced surgical stress,
  • improved well-being,
  • Often, a faster return of bowel function.

Common Cancer-Diet Myths — And What the Evidence Actually Says

“There’s a diet that can cure cancer.”

There isn’t. Long-term lifestyle patterns matter far more.

“Avoid soy.”

Whole soy foods are safe and sometimes protective.

“You can change your body’s pH with food.”

You can’t. Blood pH is tightly regulated.

“Sugar feeds cancer.”

All cells use glucose. Cutting carbs doesn’t “starve cancer.”

“You must follow a strict diet to stay well.”

Restrictive diets increase stress. Balanced and flexible eating is far more sustainable.

Evidence-Based Resources

These resources offer reliable guidance for anyone wanting support with eating well during cancer treatment and recovery.

Closing Thoughts

My diagnosis didn’t happen in isolation — it collided with decades of allergies, intolerances, IBS-type symptoms, skin conditions, and a neurodivergent body I didn’t yet understand. Generic advice wasn’t always easy to follow or adapt.

If you’re navigating cancer or long-term digestive symptoms, please remember:

You deserve advice tailored to your body, your needs, and your lived reality.

There is no single “right” diet — only what supports you best.

Key Takeaways

  • The journey of understanding my health began after my bowel cancer diagnosis in October 2023.
  • Eating well during cancer treatment and recovery is crucial for gut health, energy levels, and overall wellbeing.
  • Personalised dietary strategies often outperform generic advice, especially when managing side effects and sensitivities.
  • Balanced, varied diets rich in nutrients support healing, strengthen the immune system, and aid recovery.
  • There is no one-size-fits-all diet; focus on what nourishes and stabilises your individual health.