Eat a healthy diet and help prevent cancer


  • Most people know being overweight is not good for their health and is linked to conditions like heart disease and Type 2 diabetes. By maintaining a healthy diet and staying within healthy weight guidelines, you can help to reduce your risk of cancer by 30-50% 
  • To help protect your long-term health, it is also important to eat a wide range of food including plenty of fruit and vegetables.
  • In Europe, people who follow a healthy lifestyle and stick to cancer prevention guidelines have an 18% lower risk of cancer compared with people whose lifestyle and body weight do not meet the recommendations. 
  • Figures released by the American Cancer Society suggest that unhealthy diet and excessive body weight has been linked to 11% of cancer diagnoses in women and 5% in men in the US. 

Top tips for a healthy diet to help prevent cancer

Research shows that many types of cancer are more common in people who are overweight or obese, including two of the most common types of cancer in Ireland:

  • Breast cancer
  • Bowel cancer.

Other cancers that are linked with obesity include cancers that are particularly hard to treat:

  • Pancreatic cancer
  • Oesophageal (food pipe) cancer
  • Gallbladder cancer.

Other cancers associated with being obese are:

  • Kidney cancer
  • Womb cancer (endometrial cancer)
  • Cervical cancer
  • Thyroid cancer
  • Leukaemia (bone marrow)
  • Stomach
  • Liver cancer
  • Ovarian cancer.

Obesity is linked with so many types of cancer because fat cells in the body are active and produce hormones and proteins that are released into the bloodstream and carried around the body. Because these substances are carried around the body via the circulatory system, these ‘chemical messengers can affect almost every part of the body and increase the risk of several different types of cancer.

Obesity in Ireland

According to the 2019 Healthy Ireland Survey:

  • Just under four in ten (37%) of people have a normal weight
  • 60% of the population surveyed were found to be overweight or obese
  • Almost one in ten (9%) of 3-year olds in lower socio-economic groups are obese compared with one in twenty (5%) in higher socio-economic groups.
  • Body mass index (BMI), cholesterol and blood pressure levels are persistently higher among lower socio-economic groups.
  • NCRI reports estimate that by 2035, over 66,000 cases of cancer will be attributed to obesity, alcohol and smoking.

Cancer on the increase

  • The number of people who get cancer is expected to increase.
  • Obesity is the main cause of cancer in non-smokers.


COVID-19's Impact on Diet and Nutrition

According to the Healthy Ireland 2021 Survey since the beginning of the pandemic:

  • 36% of people report consuming 2 or more unhealthy snack foods daily, with 24% consuming one unhealthy snack on a daily basis.
  • 29% of people consume sugar sweetened drinks on a weekly basis, with 8% drinking these on a daily basis
  • 65% of people eat fruit on a daily basis, with 75% consuming vegetables daily
  • on average, people eat 2.9 portions of fruit and vegetables daily, with 34% eating the recommended 5 portions per day or more

What is obesity?

Obesity is when you are well above the weight that is normal for a person of your height. To be obese, you must be more than 25% overweight. Body mass index (BMI) is a measure of whether you are a healthy weight for your height.

Below is a link to one example of a BMI calculator that you can use to work out if you are a healthy weight

Click here

To be a healthy weight your BMI should be between 18 and 25:

  • Under 18 means you are underweight
  • Between 25 and 30 you are overweight
  • Over 30 you are obese
  • Over 40 you are very obese.
  • Cervical cancer
  • Thyroid cancer
  • Leukaemia (bone marrow)
  • Stomach
  • Liver cancer
  • Ovarian cancer.

Obesity is linked with so many types of cancer because fat cells in the body are active and produce hormones and proteins that are released into the bloodstream and carried around the body. Because these substances are carried around the body via the circulatory system, these ‘chemical messengers can affect almost every part of the body and increase the risk of several different types of cancer.

The key to healthy eating

Healthy eating can be achieved using countless different food choice combinations. You can have a healthy diet using foods you prefer due to your age, culture or traditions.

A healthy diet is the right amount and variety of different foods that give you all the calories (energy) and nutrients you need to meet the particular needs of your body. This will allow it to:

  • Grow and develop normally during childhood
  • Nourish you well as an adult
  • Allow you to reach old age with as little disease and disability as possible.

The right amount and variety of foods and drinks will differ from person to person according to:

  • Age
  • Body size
  • Lifestyle.

Some people will have unusual needs, such as athletes or people with certain medical conditions. However, most of us will need about the same balance of different foods and drinks.

A healthy diet is based mainly around plant foods, with:

  • Plenty of vegetables and fruits
  • Some pulses (legumes) like beans and peas
  • Wholegrain bread and other starchy foods like pasta and rice.

These food types provide the body with the nutrient they need to develop and maintain good health. 

Latest Irish guidelines for a healthy diet

Five food groups

Enjoy a wide variety of foods from the five food groups:

  • Vegetables and legumes (beans)
  • Fruit
  • Grain (cereal) foods, mostly wholegrain and high fibre
  • Lean meats and poultry, fish, eggs, tofu, nuts and seeds
  • Milk, yoghurt, cheese.

Watch those portions

Keep an eye on your serving sizes – choose smaller serving sizes and add plenty of vegetables, salad and fruit.

In the past we have used the food pyramid to as a guide to the foods we should be eating. In 2011, the USDA replaced the food pyramid model to the now widely used MyPlate template. 

MyPlate is divided into four sections of approximately 30 percent grains, 40 percent vegetables, 10 percent fruits and 20 percent protein, accompanied by a smaller circle representing dairy, such as a glass of milk or a yogurt cup.

This format has been praised by medical professionals as an easy and instant way for people to view their plate and ensure they are receiving the right portions of good foods with each meal.

The best calories for a healthy weight come from:

  • Plain wholemeal breads
  • Cereals
  • Potatoes
  • Pasta and rice.

Base your meals on these simple foods with plenty of vegetables, salad and fruit.

Eat plenty of different coloured vegetables, salad and fruit – at least five a day.

Dairy - Low-fat milk, yoghurt and cheese are best – choose milk and yoghurt more often than cheese.

Protein - Choose lean meat and poultry; include fish (oily is best) and remember, peas, beans and lentils are good alternatives.

Healthy oils- Use polyunsaturated and monounsaturated spreads and oils sparingly. For example, use rapeseed oil for cooking and canola oil for baking.

Avoid frying -Grill, bake, steam or boil food, instead of frying or deep frying.

Limit treats -You can enjoy healthy eating with limited amounts of ‘other foods’ like biscuits, cakes, savoury snacks and confectionery. These foods are rich in calories, fat, sugar and salt so remember – not too much and not too often.

Salt -Limit your salt intake.

Water - Drink plenty of water. It is recommended that you drink 8 cups of water, or 2 litres of water per day to keep your body hydrates and healthy. 

Vitamin D - Everyone should take a daily vitamin D supplement. 5 micrograms per day for those aged 5-50 years and 10 micrograms per day for those aged 51 years and over.

Diet Essentials:

The things you would expect-

Fruit and vegetables:

Fruit and vegetables are so important because they are ‘protective’ foods that help prevent some cancers. Fruit and vegetables provide fibre as well as a whole array of beneficial vitamins and minerals such as vitamin C, the B vitamins, potassium and magnesium.

Fruit and vegetables also provide a wide variety of other substances called phytochemicals, flavonoids and phytoestrogens which are thought to protect your health.

To get the most from fruit and vegetables, you should eat a variety of different coloured fruit and vegetables often. Choose:

  • Dark green vegetables such as broccoli, spinach, cabbage
  • Orange or red fruit and vegetables such as oranges, tomatoes, carrots, and red, orange, or yellow peppers.


Milk, yoghurt and cheese are all dairy foods, and they provide calcium which is needed for the health of your bones. However, the fat in these foods is mainly saturated fat (animal fat) which can raise blood cholesterol, which in turn, can contribute to heart disease.

Therefore, the best choices from this food group to include daily are reduced-fat or low-fat milks and yoghurts. These still contain calcium but contain very little saturated fat.

Milk is one of the most complete foods, providing the body with most of the nutrients it needs.

Dairy foods are also a good source of B vitamins, such as riboflavin, B12, vitamin A and protein.

Meat, poultry and fish 

Eat modest amounts of lean meat, poultry or fish. A low intake of red meat and, in particular, processed meat and a low intake of salt, and of salty or salted foods, are recommended to prevent bowel and stomach cancers.

What is ‘red meat’

‘Red meat’ refers to beef, pork, and lamb from domesticated animals, including that contained in processed foods and in most beef burgers. It does not include poultry or wild game.

Although eating a lot of red meat increases the likelihood of developing bowel cancer, red meat is also a good source of several nutrients. As a guide, it is recommended to avoid eating more than about 500 grams of red meat per week (500 grams cooked weight, which is equivalent to about 700–750 grams raw weight, depending on the cut and how it is cooked).

What is processed meat

‘Processed meat’ is meat that is preserved by smoking, curing, or salting, or by adding chemical preservatives. This includes:

  • Ham
  • Bacon
  • Salami
  • Some sausages like frankfurters.

Because eating processed meat is linked to the risk of bowel cancer, even in smaller amounts, and gives you no extra nutrition over red meat, you should avoid processed meat as much as possible, to reduce your cancer risk.

The things you wouldn’t expect:


Carbohydrates (carbs) are essential when watching your weight and low-carbohydrate diets are not good for health.

  • Wholemeal breads, cereals and potatoes provide the best energy (calories) for the body to work so you should not be tempted to cut these important foods from your diet. However, you can choose the carbohydrates that are healthiest and have fewer calories than others.
  • You can use different types of breads and rolls for variety.  Some types may contain more calories than others. Two slices of ‘thick cut’ pan bread or a bagel for instance, contain almost twice the calories as a bowl of porridge or a medium potato.
  • Switch from white bread to wholemeal bread.
  • Never skip meals, especially breakfast
  • Porridge is a great way to start the day as it is very filling and low in calories. Muesli on the other hand tends to be high in calories.

Although you should limit drinks and foods that are high in calories because they make you more likely to gain weight, there are some foods that are a valuable part of a healthy diet even though they are high in calories.


Cheeses, (especially full-fat cheese) are rich in fat. They can add variety, but people should avoid overdoing it. Having cheese a few times a week is better than every day.

When you eat cheese, reduced-fat cheeses like Edam or Blarney or reduced-fat cheddar are better choices.

Some soft cheeses like cottage cheese are low in fat, but these are fairly low in calcium too so serving sizes tend to be larger.

Foods like fromage frais and ice-cream contain lower quantities of calcium compared to yoghurts or milk. In addition, they have the disadvantage of being higher in fat and sugar.

Olive oil is healthy

A small amount of particular types of fat in our diet is essential for health, however, most of us eat far more fat than we need, and especially the less healthy types of fat.

Some oils used in cooking and for dressings are healthy and:

  • Low in saturated fats (the type that increase blood cholesterol)
  • High in unsaturated fats (which may help to lower blood cholesterol.

For example, olive oil is rich in mono-unsaturated fats. Using olive oil in modest amounts for cooking or as a dressing is fine as part of a healthy diet.

Nuts and seeds

Many types of nuts, such as almonds, walnuts, Brazil nuts, or hazelnuts, as well as peanuts and seeds like pumpkin seeds, are also rich in healthy oils. You can eat about a handful of these a day as part of your healthy diet.


If you drink alcohol of any type, limit your intake. Not drinking alcohol is better for cancer prevention and helps you avoid putting on weight.

To learn more about making healthy diet choices, see our FAQ section with Dietician and Nutritionist Aveen Bannon by clicking here

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