Claims are sometimes made that “low carb diets are a fad” and “there needs to be scientific evidence to demonstrate they are both safe and effective“. What is the evidence?
In fact, a low carbohydrate diet is not new and was the standard recommendation for treating Diabetes prior to the discovery of insulin. More than 150 years ago, the first weight-loss diet book (ironically written by William Banting, a distant relative of Sir Frederick Banting, the co-discoverer of insulin) focused on the limiting the intake of carbohydrates, especially those of a starchy or sugary nature. The book was titled Letter on Corpulence — Addressed to the Public (1864) and summarized the advice of the author’s physician, Dr. William Harvey that had enabled Banting to shed his portly stature’.
Recent 10 week results of a nonrandomized, parallel arm, outpatient intervention using a very low carb diet which induced nutritional ketosis was so effective at improving blood sugar control in Type 2 Diabetes, that at the end of six months >75% of people had HbA1c that was no longer in the Diabetic range (6.5%). Details of the findings from this study titled A Novel Intervention Including Individualized Nutritional Recommendations Reduces Hemoglobin A1c Level, Medication Use, and Weight in Type 2 Diabetes are available here.
I recently reviewed 2 two-year studies that demonstrated that low carb diets are both safe and effective for weight loss and improving metabolic markers;
- This long-term study titled Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet clearly demonstrated that a low carb non—calorie-restricted diet was both safe and effective and produced the greatest weight loss, lower FBS and HbA1C, the most significantly lower TG and higher HDL and lower C-reactive protein (when compared with a low-fat calorie-restricted diet and a Mediterranean calorie-restricted diet).
- This 2-year, randomized control study of more than 300 participants titled Low Fat Calorie Restricted Diet versus Low Carbohydrate Diet — a two year study found that both diet groups achieved clinically significant and nearly identical weight loss (11% at 6 months and 7% at 24 months) and that people who ate the low-carbohydrate diet had greater 24-month increases in HDL-cholesterol concentrations than those who ate a low-fat calorie restricted diet. As well, a significant finding of this study was a very favourable lowering of LDL for the first 6 months and lowering of both TG and VLDL for the first year.
These long-term data provide evidence that a low-carbohydrate diet is both a safe and effective option for weight loss and that this style of eating has a prolonged, positive effect on metabolic markers.
But is this all the evidence we have? By no means!
Below is a list of research studies and meta-analyses (complied by Dr. Sarah Hallberg) that used a low-carb intervention. These span 18 years, 76 publications, involve 6,786 subjects, and include 32 studies of 6 months or longer and 6 studies of 2 years or longer. At the bottom of this post is a downloadable pdf of this list. [Note: text in green represents meta-analyses.]
Hardly a passing fad!
Low carb diets have been well-studied and found to be both safe and effective.
Many thanks to Dr. Sarah Hallberg, a Physician and exercise physiologist from West Lafayette, Indiana (Twitter: @DrSarahHallberg) for compilation of this list.
A complete list of the Low Carb Diet studies to date (compiled by Dr. Sarah Hallberg) is available here.
You can follow me at:
https://www.facebook.com/lchfRD/
Copyright ©2018 The LCHF-Dietitian (a division of BetterByDesign Nutrition Ltd.)
LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only. The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything you have read or heard in our content.