The Effect of Low-Carbohydrate Diet on Glycemic Control in Patients with Type 2 Diabetes Mellitus

Abstract

Objective: In China, a low-fat diet (LFD) is mainly recommended to help improve blood glucose levels in patients with type 2 diabetes mellitus (T2DM). However, a low-carbohydrate diet (LCD) has been shown to be effective in improving blood glucose levels in America and England. A few studies, primarily randomized controlled trials, have been reported in China as well. Method: Firstly, we designed two ‘six-point formula’ methods, which met the requirements of LCD and LFD, respectively. Fifty-six T2DM patients were recruited and randomly allocated to the LCD group (n = 28) and the LFD group (n = 28). The LCD group received education about LCD’s six-point formula, while the LFD group received education about LFD’s six-point formula. The follow-up time was three months. The indicators for glycemic control and other metabolic parameters were collected and compared between the two groups. Results: Forty-nine patients completed the study. The proportions of calories from three macronutrients the patients consumed met the requirements of LCD and LFD. Compared to the LFD group, there was a greater decrease in HbA1c level in the LCD group (−0.63% vs. −0.31%, p < 0.05). The dosages of insulin and fasting blood glucoses (FBG) in the third month were lower than those at baseline in both groups. Compared with baseline values, body mass index (BMI) and total cholesterol (TC) in the LCD group were significantly reduced in the third month (p < 0.05); however, there were no statistically significant differences in the LFD group. Conclusions: LCD can improve blood glucose more than LFD in Chinese patients with T2DM. It can also regulate blood lipid, reduce BMI, and decrease insulin dose in patients with T2DM. In addition, the six-point formula is feasible, easily operable, and a practical educational diet for Chinese patients with T2DM.

Improving the scientific rigour of nutritional recommendations for adults with type 2 diabetes: A comprehensive review of the American Diabetes Association guideline‐recommended eating patterns

“…All 27 studies reported outcomes data for people with T2D and thus were appropriate for consideration in the development of nutritional recommendations for T2D management. Of the 10 RCTs, all of which reported on glycaemic control, nine found that a low‐carbohydrate diet resulted in a significant change from baseline to end of study; six also found a superior between‐group reduction favouring the low‐carbohydrate diet . While some studies found that the control diet also improved glycaemic control significantly from baseline, none found the control diet superior to the low‐carbohydrate diet.…”

“…Of the 10 RCTs, all of which reported on glycaemic control, nine found that a low-carbohydrate diet resulted in a significant change from baseline to end of study 86,87,89,90,[92][93][94]96 ; six also found a superior betweengroup reduction favouring the low-carbohydrate diet. 86,87,90,92,94,96 While some studies found that the control diet also improved glycaemic control significantly from baseline, none found the control diet superior to the low-carbohydrate diet. All 12 single-arm and nonrandomized trials found that a low-carbohydrate diet significantly improved glycaemic control from baseline to end of study; the two studies that made between-group comparisons found the lowcarbohydrate diet superior to the control diet.…”

“…Of 11 studies that reported on diabetes medication use, 84,88-92,97,99,103,104,106 eight reported more medication reductions and/or elimination of glycaemic control medications in the lowcarbohydrate arm. Five of six studies that conducted between-group comparisons of medication use found the low-carbohydrate diet to be superior, 86,88,89,91,99 and one study 92 found that both diets reduced usage significantly from baseline with no between-group difference.…”

“…These 42 separate studies included 22 randomized trials, 10 non-randomized trials and 10 systematic reviews, eight of which included a meta-analysis. Ten of the trials had >100 participants, 28,73,74,76,78,90,91,97,99,101 and 16 provided longer-term data: 10 studies lasting 1 to 2 years, 28,69,73,76,84,92,94,99,103,105 five studies lasting 2 years, 36,78,88,91,97 and one study providing follow-up data at 3 years. Of six studies lasting ≥2 years, 36,78,88,91,97,98 five sustained a clinically meaningful HbA1c reduction (of at least 0.7% from baseline).…”

Blood Type Diets (BTD) and Aging: An Overview

“…Since it was launched in 1996, several physicians have experimented (through empirical observations) with the diet and have found strong evidence in favor [14][15][16][17]. Nevertheless, it is reported that there's a lack of evidence supporting the BTD hypothesis [18]. To date, only one serious mechanistic explanation, apart from the lectin hypothesis, has been put forward for BTD and involves the intervention of glycans [11].…”