This site is intended for non healthcare professionals. For the professional site, please click here

06/16/2009 - Articles

A Low-Carb Diet Improves Type 2 Diabetes

By: Robert W. Griffith, MD

A low-carb diet is known to help overweight type 2 diabetics in the short term, but so far there has been little evidence of its long-term usefulness. Now a study from Sweden shows that it can help control weight, blood sugar, and blood pressure for almost 2 years in motivated patients.

A low-carb diet is known to help overweight type 2 diabetics in the short term, but so far there has been little evidence of its long-term usefulness. Now a study from Sweden shows that it can help control weight, blood sugar, and blood pressure for almost 2 years in motivated patients.

Summary

If obese people with type 2 diabetes continue to eat a low-carb diet (with restricted calories) it will benefit their body weight and blood glucose control for at least 22 months.

Introduction

Diabetics often loose heart with their diets - they don't see the benefits too clearly, and recent reports about the poor long-term results with the Atkins diet haven't helped. However, it's clear that a low-carb diet improves type 2 diabetes, and now it's been studied over a 22-month period in a Swedish study. The results are reported in the journal Nutrition & Metabolism, and we summarize them here.

What was done

The researchers had previously reported the results obtained in 16 type 2 diabetes patients with obesity given a 20% carbohydrate diet for 6 months. Compared with 15 similar 'control' patients given a 55% to 60% carb diet, there was significantly better control of blood sugar levels and body weight. After 6 months, the controls reverted to different diets, but those on the low-carb diet were kept in study, and followed for a total of 22 months.

The patients were advised to follow diets containing 180 calories for men and 1600 calories for women. The proportions of calories were: carbs 20%, protein 30%, and fat 50%. The carbs consumed were limited to vegetables, salad and crisp bread - no other bread, pasta, potatoes, rice, or breakfast cereal. They were also recommended to walk 30 minutes each day, and take a multivitamin supplement with extra calcium in it.

The control group was advised to consume diets with the same calorie contents, but with the following make-up: carbs 55% - 60%, protein 15%, and fat 25% - 30%. Seven of them switched to a 20% carb diet after 6 months, and 3 more switched between 6 months and 22 months; the remaining 5 stayed on their original diet make-up.

Body weight, body mass index (BMI), HbA1c, and lipid profile were measured at baseline, and at 3, 6, and 22 months. Medication use was recorded at baseline, 6, and 22 months.

What was found

The average values for the 16 subjects in the 20% carb group are given in the table:

  Baseline 3 months 6 months 22 months
Weight (lbs) 222 203* 197* 214*
BMI 36.1 33.0* 32.0* 32.9*
HbA1c (%) 8.0 5.9* 6.6* 6.9*
Total cholesterol 217 224 236 220
HDL cholesterol 43 46 50* 50*
Triglycerides 124 106 124 124

 

* signifies a statistically significant difference from baseline value

Although the average weight increased from month 6 to month 22, seven of the 16 patients retained the same body weight or reduced it during this time. After 6 months, two of 5 patients taking sulphonylureas had discontinued this type of medication, and 3 had reduced their dosage. Three of 11 subjects taking insulin at baseline had discontinued by month 6, and the other 8 had reduced their dosage; during the next 15 months two of them restarted insulin treatment because of increasing weight.

There were no adverse cardiovascular effects in the 16 patients over the 22-month period, whereas there were 3 episodes among the 5 patients who never changed from the 'control' diet between 6 and 22 months.

Fourteen of the 16 patients were on blood pressure medication at the start of the study. Five reduced the dosage during the first 6 months, and didn't increase them again. Blood pressures remained well controlled.

What these results mean

The short-term effects of a low-carb diet on body weight are already established. The long-term benefits have been less well studied, however. In this extension of a 6-month study, there was a lasting effect on body weight, blood sugar control, blood pressure, and high-density lipoprotein (HDL) cholesterol levels. There were no detrimental effects.

The researchers state that these type 2 diabetic patients with obesity were motivated to stay with the low-carb diet because of the reduced feeling of hunger (compared with other diets they had tried) and the encouraging feedback they got from self-monitoring of blood glucose. The ability to reduce antidiabetic medications was an added signal of continuing success. Altogether, an encouraging study for people with type 2 diabetes.

Source

  • Low-carbohydrate diet in type 2 diabetes. Stable improvement of bodyweight and glycaemic control during 22 months follow-up. JV. Nielsen , EA. Joensson, Nutrition & metabolism, 2006, vol. 166, pp. 1186--1743

 

Related Links
Low Carb Diets Produce Fast Results in Diabetics
Side Effects of Low Carb Diets
Low Carb Diet Recipes

Created on: 07/28/2006
Reviewed on: 06/16/2009

Your rating: None

Add your comment

  • Allowed HTML tags: <em> <strong> <cite> <ul> <ol> <li> <dl> <dt> <dd>
  • Lines and paragraphs break automatically.

More information about formatting options

CAPTCHA
This question is for testing whether you are a human visitor and to prevent automated spam submissions.
Image CAPTCHA
Copy the characters (respecting upper/lower case) from the image.