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Consumption of carbohydrate in people with diabetes

In response to many enquiries from people with diabetes and healthcare professionals, Diabetes UK has produced this information to clarify our position on carbohydrates for people with diabetes.

It is important to include some carbohydrate as part of a healthy balanced diet for all people with diabetes. All dietary information by Diabetes UK is evidence-based.

In May 2011, Diabetes UK published evidence-based recommendations for the practical implementation of nutrition advice in the UK. The criteria for the grading of recommendations were based upon a paper by Petrie et al on behalf of the Scottish Intercollegiate Guidelines Network. The working group consisted of experts in the field of diet and diabetes. This was published in the peer-reviewed journal Diabetic Medicine (1).

Why does your body need carbohydrates?

Carbohydrate is our body’s preferred source of energy in the diet. All carbohydrates are broken down into glucose which is essential fuel for the body, especially the brain. The body aims to maintain a constant glucose level in the bloodstream at all times. The body keeps a store of glucose as glycogen in the liver for times when we are fasting or need extra glucose
If carbohydrate intake is severely restricted and glucose stores are exhausted, the fat stores start to be broken down and used as energy. During this process, by-products called ketones are produced in the body. This is called ketosis.

In what foods is carbohydrate present?

Carbohydrate is present in starchy carbohydrate foods such as breads, potatoes, pasta, rice, beans and pulses, as well as in fruit, some vegetables, some dairy foods and sugars.

How much carbohydrate do you need?

The guidelines daily amount (GDA) for carbohydrate is 230g for women and 300g for men. These are general guidelines: the actual amount of carbohydrate that the body needs varies depending on your age, weight, and activity levels. The amount of carbohydrate eaten or drunk is the major factor in blood glucose control and therefore portion sizes are important. The advice provided by Diabetes UK is for the general population with diabetes; it does not replace individual advice from a healthcare professional.

Dietary recommendations

It is important to note that the two types of diabetes are different and may need to be managed differently. For example, factors to consider include the type of medication and or insulin; physical activity; overall diabetes control; or lifestyle. One thing the two types of diabetes do have in common is an increased risk of cardiovascular disease (this includes heart disease), which is a major cause of death and disability in people with diabetes. Cardiovascular disease accounts for 44 per cent of fatalities in people with Type 1 diabetes and 52 per cent in people with Type 2 diabetes (2), so a cardio-protective diet is important for both.

Type 2 diabetes

Diabetes UK produced a position statement on low-carbohydrate diets for people with Type 2 diabetes who want to lose weight. Diabetes UK reviewed the evidence and reached the following conclusions:

  • Evidence exists suggesting that low-carbohydrate diets can lead to improvements in HbA1c and reductions in body weight in the short term (less than one year).
  • Weight loss from a low-carbohydrate diet may be due to a reduced calorie intake and not specifically as a result of the carbohydrate reduction associated with this diet.
  • Despite the short-term benefit there is a lack of evidence related to the long-term safety and benefit of following this diet.

Diabetes UK recommends the following:

  • A range of approaches to weight loss should be considered with the overall aim of energy intake being less than energy expenditure; the most appropriate method to achieve this should be identified between the person with diabetes and their dietitian.
  • When considering a low-carbohydrate diet as an option for weight loss, people with diabetes should be made aware of possible side effects such as the risk of hypoglycaemia, headaches, lack of concentration, and constipation.
  • Individual diabetes control should be considered – blood glucose levels need to be closely monitored, with adjustments to medications as required.
  • Nutritional adequacy should be considered. It should be ensured that optimal amounts of vitamins, minerals and fibre are supplied by the diet.
  • The amount of carbohydrate to be restricted should be agreed between the person with diabetes and their dietitian.

Type 1 diabetes

If a person with Type 1 diabetes is of normal weight (ie they do not wish to lose any weight and their blood glucose levels are well controlled), they do not need to reduce their carbohydrate intake. Intervention studies have failed to show any significant effect on glycaemic control of manipulating carbohydrates (3, 4, 5). On a meal-by-meal basis, matching insulin to the amount of carbohydrate consumed is an effective strategy in improving glycaemic control. Randomised controlled trials have shown that carbohydrate counting can improve glycaemic control, quality of life and general well being (6,7,8,9) without increases in severe hypoglycaemic events, body weight or blood lipids (10, 11). Therefore, a person with diabetes can follow the same balanced diet as anyone else.

We are aware that some people with Type 1 diabetes may choose to reduce their carbohydrate intake in order to manage their glycaemic control, reduce their insulin intake or to lose weight. Diabetes UK does not recommend this because there is currently insufficient evidence to show whether this is effective in managing Type 1 diabetes in the long term. We also do not know whether it may have long term detrimental effects on health. People who choose to reduce their carbohydrate intake should speak to their healthcare professionals for specific advice as they will need to adjust their insulin. It is important to be aware that because a low carbohydrate diet tends to be higher in fat and protein, this may impact on long term cardiovascular and kidney health so these need to be monitored as part of your annual review.

Glycaemic index (GI)

While we are aware that a UK database is being produced, it is not available at the moment. The University of Sydney has a database consisting of many different foods from different countries, but is not always UK specific.

GI values for a specific food can vary depending on the group of people they are tested on, the country and year of manufacture, and different varieties. A good example of this is rice, where the different varieties of rice will have different GI values, regardless of whether they are brown or white (the length of the grain seems to be a better indicator). This is because different varieties of rice have different amylose:amylopectin ratios, which affects the rate of digestion. The variability of GI values means that GI can be interpreted wrongly to make a desired argument, for example in the case of Shredded Wheat, which has been tested twice, giving a value of 67 (med GI) and 83 (high GI).

Books on GI values are available in the UK, but their accuracy cannot be confirmed because they either use data not specific to UK foods, or because they are produced by companies who are reliant on manufacturers’ information.

The dietary information on the Diabetes UK website will be updated to reflect these guidelines.


In order to make clear decisions on working with Diabetes UK and partnerships with food manufacturers, retailers and service providers, Diabetes UK uses the traffic light labelling system to determine if we can work with a company or not. At present Diabetes UK strives to reflect the Eat-well Plate, which encompasses a healthy, well-balanced diet, and in turn would like any partners and sponsors with which we work to reflect this.

Any product considered to work in partnership with Diabetes UK needs to contain at least two green lights, no more than two amber lights and no red lights, with the exceptions of:

  • Oils and spreads which must come from an unsaturated source such as (olive, sunflower, or peanut oil) rather than a saturated source
  • Unsweetened fruit juices and smoothies
  • Products containing high sugar content from a natural source of sugar (to be considered on an individual basis)
  • Oily fish
  • Nuts/seeds (plain)

We seek to ensure that those we work with and the ways that we work with them are consistent with our organisational values. Consequently, all relationships are based on the principles of integrity and openness, maintenance of independence, equality in partnership and mutual benefit for all concerned.

Any such initiatives will not compromise the independent status of Diabetes UK. If there is a possibility that the independence, reputation or credibility of Diabetes UK is jeopardised, we will review the risks versus the potential benefits for people with diabetes and may withdraw from the initiative.


  1. P. A. Dyson, T. Kelly, T. Deakin, A. Duncan, G. Frost, Z. Harrison, D. Khatri, D. Kunka, P. (2011) Diabetes UK evidence-based nutrition guidelines for the prevention and management of diabetes. Diabetic Medicine 28 (11); 1282-1288
  2. Diabetes in the UK 2011/2012: Key statistics on diabetes
  3. Strychar I, Meltzer S, Cohn J et al (2009). Effects of a diet higher in carbohydrate/lower in fat versus lower in carbohydrate/higher in monounsaturated fat on post-meal triglyceride concentrations and other cardiovascular risk factors in Type 1 diabetes. Diabetes Care 32 (9); 1597–1599.
  4. Simpson R, Mann J, Eaton J et al (1979). High-carbohydrate diets and insulin-dependent diabetics. British Medical Journal 2; 523–525.
  5. Hollenbeck C, Connor W, Riddle M et al (1985). The effects of a high-carbohydrate
    low-fat cholesterol-restricted diet on plasma lipid, lipoprotein, and apoprotein
    concentrations in insulin-dependent (Type 1) diabetes mellitus. Metabolism 34 (6); 559–566.
  6. The DCCT Research Group (1993). Nutrition interventions for intensive therapy in the diabetes control and complications trial. J Am Diet Association 93; 768–772.
  7. Muhlhauser I, Jorgens V, Berger M et al (1983). Bicentric evaluation of a teaching and treatment programme for Type 1 (insulin-dependent) diabetic patients: improvement of metabolic control and other measures of diabetes care for up to 22 months. Diabetologia25; 470–6.
  8. Muhlhauser I, Bruckner I, Berger M et al (1987). Evaluation of an intensified insulin
    treatment and teaching programme as routine management of Type 1 (insulin-dependent)diabetes. The Bucharest-Düsseldorf Study. Diabetologia 30; 681–90.
  9. Bott S, Bott U, Berger M et al (1997). Intensified insulin therapy and the risk of severe hypoglycaemia. Diabetologia 40; 926–32.
  10. DAFNE Study Group (2002). Training in flexible, intensive insulin management to enable dietary freedom in people with Type 1 diabetes: dose adjustment for normal eating (DAFNE) randomised controlled trial. British Medical Journal 325; 746–752.
  11. Shearer A, Bagust A, Sanderson D et al (2004). Cost effectiveness of flexible intensive
    insulin management to enable dietary freedom in people with Type 1 diabetes in the UK.Diabetic Medicine 21 (5); 460–67.