NOTE: This article was first published in Spring 2020 in Issue 8 of our Kidney Matters magazine

Managing a diet to accommodate both diabetes and chronic kidney disease (CKD) can be challenging as there is no ‘one size fits all’ recommended diet. But with 29% of the kidney patient population also having to tackle diabetes, providing trusted and easy to follow dietary advice to ensure good nutrition and a varied, healthy diet is vital.

In this article, we look at important aspects of the diet and give some tips which may help you make healthier food choices to help manage your diabetes and CKD. However, if you have been given specific dietary advice by your dietitian you should continue to follow this.

Carbohydrates

Carbohydrates are the body’s main source of energy; they also provide important nutrients and help give us a balanced diet. These carbohydrates are broken down into glucose and used by the body as fuel.

There are two main types of carbohydrates –

Starchy carbohydrates which includes cereals, bread, pasta, potatoes, yam and couscous. The type and amount you eat can make a difference to your blood glucose levels. Choosing carbohydrates that have a lower glycaemic index (GI) like wholegrain bread, whole-wheat pasta, basmati, or brown rice, will raise your blood glucose levels much slower.

When choosing your starchy carbohydrates, bear in mind some of these can be high in potassium. This is important if you are following a low-potassium diet.

The table below gives some examples.

Sugars are split into two types:

Natural sugars such as those in fruit and dairy foods which are part of a healthy, balanced diet.

Added sugars like those we add to hot drinks, or those in sugary drinks, sweets, biscuits, cakes and chocolate, which should be limited.

Fruit and vegetables

Fruit and vegetables are a great source of vitamins, minerals and fibre and can be a good snack if you are trying to lose weight. Eating fruit and vegetables is known to significantly reduce some type of cancers and prevent some diseases. We should be aiming for at least five-a-day, even if you are on a low-potassium diet. Fruit does contain some natural sugars so it’s a good idea to watch the portion size. As a rough guide, a portion is the amount that will fit in the palm of your hand e.g. 1 medium apple, 7 strawberries or 2 clementines.

Some fruit and vegetables are a source of potassium, and if you are on a low-potassium diet you should opt for lower-potassium fruits and vegetables. The table above provides some examples.

When you boil vegetables such as broccoli, green beans and cauliflower the potassium leaches out into the water, lowering the potassium content. Discard the water rather than using it for gravy or stock.

Fruit juices and smoothies are often not recommended in diabetes (or when you are following a low-potassium diet). These drinks contain fruit in large quantities, and often have added sugar. The process of making these drinks means that the sugar in the drink goes into your blood stream faster, increasing your blood glucose levels quickly.

Hypoglycaemia (or hypos)

Hypoglycaemia (known as a ‘hypo’) is when the blood glucose drops below 4mmol/L and leaves you feeling shaky, sweaty, hungry and with blurry vision and/or palpitations. This can happen for various reasons - too much insulin, missing a meal, not enough carbohydrates at mealtimes, increased exercise, being on haemodialysis and the potential need for less insulin in advanced kidney disease. It is important to treat a hypo as soon as possible.

To treat a hypo, you need to follow two steps:

STEP 1: drink or eat some fast-acting carbohydrate (15-20g) — see on the right for some examples. Some hypo treatments may need to be avoided if you are on a low-potassium diet or fluid restriction.

STEP 2: to prevent your blood glucose dropping again you need to eat some starchy carbohydrate. If it’s not close to a mealtime you could have a snack such as:

• A piece of fruit (low potassium if necessary)
• A small sandwich
• A couple of digestive biscuits
• A small bowl of cereal (low potassium if necessary, such as Weetabix)
• A slice of toast

If you are experiencing frequent hypos, you should speak to your diabetes team.

It is possible to enjoy your food if you have diabetes and CKD, and we hope this information will encourage you to experiment with the foods you enjoy. For more individualised advice, get in touch with your dietitian.

To read more on how to lower your potassium levels read our leaflet, Lowering your potassium levels.

Many of the recipes on our Kidney Kitchen website are suitable for people with diabetes and CKD.