Personalised Nutrition During Cancer

By Meredy Birdi, HCPC-registered Cancer Dietitian and Nutritional Therapist

 

“What should I be eating?”

“Is there anything I should avoid?”

“Should I be taking supplements?”

“I've read so many different things about cancer and nutrition, my head is spinning. How do I know which is right? And which of it applies to me?”

These are questions I hear regularly from people I meet in my clinic. There is such a lot of information about cancer and nutrition, and so many things you're told you “should” and “shouldn't” be doing. It can be difficult to know what to believe or trust.

Food can also take on a whole new significance after a cancer diagnosis. Things you used to eat without giving them much thought can become a source of questions and worry.

Nutrition doesn't need to become another thing you worry about getting right. It's something that can really help you through cancer treatment and beyond.

How Good Nutrition Can Help

Good nutrition can make a real difference during cancer treatment. It can help you maintain muscle mass, strength and energy, support your immune system, manage treatment side effects and tolerate treatment better. It also plays an important role in helping your body heal and recover.

And its benefits don't stop when treatment finishes. Nutrition can help you rebuild your strength, manage ongoing or late effects of treatment, and support your longer-term health.

If you have advanced cancer, nutrition can help you manage symptoms, maintain your strength and energy, and support your quality of life.

Getting ‘Match Fit’ for Treatment

If you're about to start treatment, this is a perfect time to look at your nutrition. It's a window of opportunity to get yourself as well prepared as possible before you start.

This period is called prehabilitation, and it brings together nutrition, physical activity and emotional wellbeing. One of my clients described it as getting "match fit" for treatment. I absolutely loved that expression, and I've borrowed it ever since!

We look at your nutritional needs, answer any questions or concerns you have, and help you build or maintain your strength and stay as well nourished as possible. Muscle mass and strength are really important, and I keep a close eye on both throughout treatment, recovery and beyond.

Preparing also means thinking ahead. If you're starting chemotherapy, for example, we'll talk about what you could do if your appetite changes, you feel nauseous or you're too tired to cook.

We plan together. That might mean cooking a little extra now so you can put some nourishing meals in the freezer, having a few easy options in the fridge and keeping some store cupboard staples ready for days when you're tired. We also think about meals, snacks and drinks that are easier to manage if eating is difficult.

I've had some lovely messages from people telling me what a difference this has made. When they weren't feeling well, they already knew what to do. They had a plan they could put into action without having to spend precious energy figuring things out at the time.

Having a Plan and Staying Flexible

How you're feeling during cancer treatment can change from week to week. You might be eating well one week and struggling with a sore mouth, taste changes or diarrhoea the next. Something you were enjoying before might now be off the menu completely.

That's why it's so important to have a plan that can change with you.

I sometimes use the London Tube map to explain this in my workshops. If you're travelling from one side of London to the other, there are usually several routes you could take. Some are quicker, some involve fewer changes, but there isn't only one way to reach your destination.

It's a great analogy for cancer nutrition. We want to help you maintain your strength and resilience. And there are lots of different ways we can do that.

If you have diarrhoea, for example, we may need to change route. We'd look at what might be contributing to it, how to keep you well hydrated and nourished, and which foods and drinks you enjoy and find easiest to manage.

There are lots of practical ways nutrition can help with treatment side effects, whether you're dealing with nausea, taste changes, a sore mouth, constipation, a poor appetite or other difficulties.

And as things change, we can adapt the plan again. That's one of the benefits of having nutritional support over time.

If you're having any difficulties with eating or drinking, you might find my practical guide to managing cancer treatment side effects helpful.

Understanding You Before Looking at Your Diet

There isn't one perfect diet or a single approach that everyone with cancer should follow. What you need will depend on your diagnosis, treatment, medical history, symptoms, weight, medications, nutritional needs and individual circumstances.

Before I give advice, I need to understand what's really happening for you.

What are you worried about? What questions do you have? Do you enjoy cooking, or not? Who prepares your meals? How much energy do you have? Who else is at home with you? What else is going on in your life?

I need to understand all of this because it's not enough for the advice to be useful. It needs to be doable in real life.

I understand how cancer care works and how important it is that nutritional advice, including any supplements, fits safely alongside your treatment.

Your priorities may be quite different depending on where you are.

If you're preparing for or going through treatment, we might focus on helping you maintain your weight, muscle mass and strength, and managing any difficulties with eating and drinking.

If you have advanced cancer, we can focus on helping you maintain your strength and energy, manage symptoms and enjoy your food, so you can keep doing the things you love.

If you've finished treatment, you may be rebuilding your strength, dealing with ongoing or late effects, or thinking about your longer-term health. You might have questions about hormone treatment, bone or heart health, managing your weight, or what you can do to reduce your risk of cancer coming back.

My Focus Is on Adding, Not Taking Away

You've probably come across plenty of advice about foods you should avoid if you have cancer. Sugar, dairy, soya and all sorts of other foods might end up on the list.

I don't believe nutrition advice should be a long list of restrictions. My focus is much more on what we can add, rather than what we should take away.

When we focus on adding more of the foods that benefit us, a natural order starts to develop. The foods we want to include more often take up more space in our diet, and the things that are less helpful tend to move further down the list. We don't have to overthink every choice or make foods off-limits unnecessarily.

I've seen how often people become frightened of eating the wrong thing and start cutting foods out because they think it's safer. But that can mean missing out on foods and nutrients that would actually benefit them.

Being able to talk through your worries about sugar, supplements or something you've read can make a huge difference. Getting clear answers can help you move on from those concerns and enjoy your food again.

If this sounds familiar, you might find my article Food Fear After a Cancer Diagnosis helpful.

Focusing on What You Need Right Now

I'm all for being proactive about nutrition and thinking ahead. But there's a big difference between being prepared and trying to tackle everything at once.

I see people worrying about things that may be months away, sometimes before they've even started their current treatment. There's a lot to think about, and trying to deal with every eventuality adds so much unnecessary pressure.

And then there's all the nutrition information coming at you from every direction. You start with the best intentions, wanting to include all the beneficial foods and nutrients you've heard about and not miss anything out. Before long, you've got a never-ending list of things you feel should be on every plate.

You can't possibly fit everything into every meal, and you don't need to.

If you're feeling unwell, it's even more important to be realistic about what you can manage. We can focus on getting you through that difficult patch without expecting you to address every aspect of your nutrition at the same time.

A big part of my role is helping you prioritise. We look at what's important for you right now, what will make the biggest difference and what can wait.

When Should I Start?

Sometimes people contact my office to ask whether they should wait until they've finished chemotherapy, radiotherapy or other treatment before starting nutritional support. They want to get the most out of it, so they feel that waiting until life is a little calmer will give them more time and headspace to focus on their nutrition and make changes.

I completely understand the thinking. But what a shame to miss out on all the help that good nutrition could be giving you during treatment. Good nutrition can help maintain muscle mass and strength, manage treatment side effects, support treatment tolerance and recovery. There are so many ways it can make a difference.

Something people don't always realise is that good nutritional support shouldn't feel like another enormous list of things to do. Quite the opposite.

We might start with one or two things, or we might do more if you have the capacity. It's about identifying what's most helpful for you and making a plan that feels achievable, whatever else you're dealing with.

People often tell me how relieved they feel when they've had their questions answered and know what to focus on. I can see the difference too. They seem lighter, more positive and even excited about what they can do to help themselves.

The sooner you get nutritional support, the sooner you can start benefiting from it.

If You'd Like One-to-One Support

If you're unsure what to eat, have questions about something you've read or heard, or would welcome some help knowing what to focus on, I'd be very happy to help.

I offer private one-to-one online cancer nutrition consultations, with support over a period of time so we can make a plan together, see how things are going and adapt it as your needs change.

You can read more about my personalised cancer nutrition programmes.

Updated October 2026

This article is for general information and isn't a substitute for personalised medical or dietetic advice.