How do you build a meal plan for a client with type 2 diabetes?

Start with the pattern, not a formula

The American Diabetes Association's 2019 nutrition consensus found no ideal split of energy between carbohydrate, protein and fat for people with diabetes. Mediterranean, lower-carbohydrate, vegetarian or vegan, DASH and lower-fat patterns can all work. Diabetes UK's 2018 guidelines take the same line.

So the best plan is the one the client will still be following in six months. Ask what they eat on a normal weekday, which meals they can't change (a work canteen, family dinners, shift patterns) and what they're willing to try. Build from there.

Carbohydrate: how much and when

Carbohydrate has the biggest direct effect on blood glucose, and the ADA consensus notes that reducing overall carbohydrate has the most evidence for improving it. How far to go depends on the client, their readings and their medication.

If you choose to set carbohydrate as a percentage of energy, convert this into grams and then distribute it across meals and snacks according to the client's usual eating pattern, glucose response and medication.

For example, for a client on 1800 kcal (about 7530 kJ) with 40% of energy from carbohydrate:

Daily carbohydrate = 1800 × 0.40 ÷ 4 = 180 g

How that 180 g is distributed across the day should then be individualised rather than automatically divided equally between meals.

Consistency in carbohydrate amount and timing can be particularly important for people using fixed insulin regimens or medications that can cause hypoglycaemia, such as sulfonylureas. People using flexible insulin dosing matched to carbohydrate intake may have more flexibility.

Very-low-carbohydrate or ketogenic diets require particular caution in people taking SGLT2 inhibitors because of the risk of diabetic ketoacidosis. Pregnancy and CKD also require condition-specific nutrition guidance.

Quality: fibre, vegetables and swaps

• Half the plate non-starchy vegetables at lunch and dinner. They add fibre and volume for very little carbohydrate.
• Wholegrains, legumes and intact grains in place of refined ones. They raise fibre, and many sit lower on glycaemic index. See glycaemic index vs glycaemic load.
• Water instead of sugary drinks. Replacing sugar-sweetened drinks with water can substantially reduce free sugar and carbohydrate intake.
• Protein at every meal, in the usual range for the client. There is no need to raise it for diabetes alone, and it should be checked if kidney function is reduced. See protein needs in kidney disease.
• Mostly unsaturated fats, from foods such as olive oil, nuts, seeds and oily fish, to support overall cardiovascular health.

Fibre targets are the same as for anyone else: 30 g a day in the UK, 25 g for women and 30 g for men in Australia and New Zealand, and 14 g per 1000 kcal in the US. Most adults eat well under that, so raise it over a few weeks with plenty of fluid.

Weight, remission and medication

For clients with overweight, losing about 5% of body weight improves glucose control and blood pressure, and more loss brings more benefit. In the DiRECT trial, almost half of participants on a primary care weight management programme, starting with a low-energy total diet replacement, were in remission at 12 months, and remission tracked how much weight people lost.

That kind of programme is run with the GP or diabetes team, who review medication before it starts. Substantial reductions in energy or carbohydrate intake can increase the risk of hypoglycaemia in people using insulin or sulfonylureas, so medication may need to be reviewed as dietary intake changes. Ask what they take, whether they have hypos, and who to contact if readings change. Medication adjustment should be managed by the client's prescribing or diabetes team. Work within your scope and refer back when medication review or specialist diabetes nutrition support is required.