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The Low-Carbohydrate Effect

Jul 25, 2020
Editor: David L. Joffe, BSPharm, CDE, FACA

Author: Bernice Ford, 2021 PharmD Candidate, Florida Agricultural & Mechanical University, College of Pharmacy and Pharmaceutical Sciences

Encouraging evidence suggests that diabetes reversal can be achieved through a modified, low-carbohydrate diet.

Precedent research has illustrated the extent to which carbohydrate consumption can affect glycemic control. Numerous studies have repeatedly established a causal relationship between a high-carb diet and the development of obesity and diabetes. Before insulin’s discovery, a diet high in fat and low in carbohydrates was the most prevalent nutritional therapy for managing diabetes mellitus. A small trial was conducted in a general practice environment to assess the significance of a low-carbohydrate diet further.


Nineteen patients with diabetes were selected to participate in an eight-month study. A dietary advice sheet was provided to illustrate the implementation of a low-carbohydrate diet. This informational document emphasized the preeminence of vegetable, protein, and fat consumption, with sugar and grain restrictions. All patients were instructed to eat when imposed by hunger, rather than deliberately reducing daily caloric intake.

Eighteen of the nineteen original participants were able to complete the trial. The trial culminated in favorable outcomes in all patients upon completion of the study. All eighteen participants displayed a reduction in weight, with the average weight loss approximately 19 pounds. A mean decrease in HbA1c from 51 to 40 mmol/mol was observed. A reduction in total cholesterol and blood pressure was also exhibited in study subjects. These dietary alterations resulted in sixteen patients no longer being classified as diabetic. They permitted the discontinuance of all medications in seven patients by the end of the eight-month trial. An overall qualitative improvement in lifestyle and vitality was reported by patients while following the low-carbohydrate diet.

The results in this study are consistent with a previous trial’s findings. A 44-month retrospective follow-up was conducted in sixteen previously studied patients that were placed on a low-carbohydrate diet. It was concluded that patients who have obesity or type 2 diabetes should be advised to adhere to a diet that consists of 20% carbohydrates to obtain lasting effects in weight management and glycemic control.

Another study conducted in eleven patients with diabetes provided the mechanistic evidence of type 2 diabetes reversal. Interpretation of gathered data found beta-cell function and hepatic insulin sensitivity normalization in study participants that were achieved solely by restricting carbohydrate consumption. A reduction in pancreatic and liver triacylglycerol stores was associated with the therapeutic function in these organs and a reversal of type 2 diabetes.

Although relevant findings were proven in this relatively small, eight-month trial, obvious limitations were present. Bias was increased with the process of self-selecting patients. Adherence to the low-carbohydrate diet was not recorded, and the study lacked a control arm. Due to fundamental standards of a quintessential clinical trial not being met with this small-scale study, the clinical significance of the definitive impact of a low-carbohydrate diet cannot be extensively assessed and compared to other restrictive diets. However, the data provided in this study demonstrates “real-world” evidence that a diet low in carbohydrates can foster weight loss and improve glycemic control in participating patients.

The essential findings unveiled in this study warrant the need for further research with a larger population and more extensive parameters. Generalizability and transferability of effects across a conglomeration of dietary choices, treatment regimens, and patient populations must be discerned before the determination of lifelong clinical significance.

Practice Pearls:

  • A diet high in carbohydrates is linked with the development of obesity and diabetes.
  • A low-carbohydrate diet that does not focus on caloric restriction can lead to weight loss, improvement in glycemic control, and reductions in blood pressure and total cholesterol.
  • Although standards of a rigorous clinical trial were not met in this study, additional evidence was obtained that suggested a diet low in carbohydrates can aid in reestablishing metabolic health.


Unwin D, Unwin J. Low carbohydrate diet to achieve weight loss and improve HbA1c in type 2 diabetes and prediabetes: Experience from one general practice. Pract Diabetes. 2014.doi:10.1002/pdi.1835

Westman EC, Yancy WS, Humphreys M. Dietary treatment of diabetes mellitus in the pre-insulin era (1914-1922). Perspect Biol Med. 2006;49(1):77-83. doi:10.1353/pbm.2006.0017

Nielsen J V., Joensson EA. Low-carbohydrate diet in type 2 diabetes: Stable improvement of bodyweight and glycemic control during 44 months follow-up. Nutr Metab. 2008;5(1):14.doi:10.1186/1743-7075-5-14

Lim EL, Hollingsworth KG, Aribisala BS, Chen MJ, Mathers JC, Taylor R. Reversal of type 2 diabetes: Normalisation of beta-cell function in association with decreased pancreas and liver triacylglycerol. Diabetologia. 2011;54(10):2506-2514. doi:10.1007/s00125-011-2204-7



Bernice Ford, 2021 PharmD Candidate, Florida Agricultural & Mechanical University, College of Pharmacy and Pharmaceutical Sciences


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