|Year : 2014 | Volume
| Issue : 2 | Page : 73-75
Eponyms in medical nutrition and nutraceuticals: The Atkins diet
Sandra D Scrivens
Alton, Hampshire, United Kingdom
|Date of Web Publication||6-May-2014|
Sandra D Scrivens
Alton, Hampshire, United Kingdom
Source of Support: None, Conflict of Interest: None
This review forms part of a series on Eponyms in Medical Nutrition and Nutraceuticals. The Atkins Diet (AD) commercial weight loss program works on the principle of producing ketones as the body's main energy source as opposed to glucose by means of a diet high in protein and fat and very low in carbohydrate (CHO). In terms of weight loss, the AD has proved more effective than a high CHO/low fat diet in the short term with both diets demonstrating similar weight loss at 12 months. Habitual concerns regarding the effect of the AD on bone and cardiovascular health appear to be unfounded although high-quality randomized-controlled trials (RCTs) are limited. The AD is contraindicated in patients with chronic kidney disease (CKD) although evidence does not indicate a negative effect on kidney function in healthy populations.
Keywords: High-protein diet, low carbohydrate diet, weight loss diet
|How to cite this article:|
Scrivens SD. Eponyms in medical nutrition and nutraceuticals: The Atkins diet. J Med Nutr Nutraceut 2014;3:73-5
| Introduction|| |
The Atkins Diet (AD), founded by cardiologist Robert Atkins in the 1970s, mimics starvation mode by severe restriction of carbohydrate (CHO) and promotion of protein and fat intake resulting in the breakdown of fat stores and production of ketones for use in place of glucose as the body's main energy source.
What is the Atkins diet?
The diet comprises an "induction" phase where permitted CHO is restricted to no more than 20 g per day with protein and fat being provided by poultry, red meat, fish, eggs, butter, cheese, cream and vegetable oils.  Whole grains, seeds, nuts, legumes and fruit may be slowly introduced along with low-calorie alcohol and caffeine during the "ongoing weight loss" and "premaintenance" phases increasing CHO by initially 5 g daily per week and subsequently 10 g daily per week until weight loss of up to 1 lb per week is achieved. During the final "maintenance" phase, additional CHO sources and other foods may be added to the diet depending on individual body requirements to sustain maintenance phase weight although CHO intake remains restricted.
Who is the Atkins diet intended for?
The AD is a commercial diet intended for weight loss. It is not recommended alongside pre-existing kidney disease.
What is the evidence for the efficacy of the Atkins diet?
Although the precise mechanisms are not fully understood, it is commonly accepted that protein intake leads to greater satiety than CHO and fat in the short and long term.  The AD, however, has historically been surrounded by controversy and despite sales of over 45 million Atkins Diet books, very few RCTs have been carried out to scientifically assess the efficacy and safety of the AD or similar diets.  The results of two independent RCTs published in 2003  and 2004  comparing obese subjects assigned to a low-CHO/high-protein/high-fat diet or a high-CHO/low-fat (conventional) weight loss diet respectively, found that subjects assigned to the low-CHO diet lost more weight than their controls at 6 months although a follow-up of the latter study found that weight loss at 1 year was similar in both groups. The authors advise caution, however, as their findings were affected by high dropout rates in both studies, modest overall weight loss and, in the latter study, poor diet compliance. A report, presented at the Nutrition Society symposium in 2011, assessing evidence for the safety and efficacy of high protein diets concluded that although a high protein diet may increase weight loss at 12 months compared to a high-CHO diet, high-CHO/low fat diets may also lead to significant weight loss over the same period while providing high-fiber intake with its associated health benefits. 
What is the evidence for the safety of the Atkins diet?
Aside from initial side effects associated with CHO and fiber restriction such as bad breath, tiredness, and constipation, much concern has been focused on whether the AD is a safe method of weight loss with concerns raised in particular regarding potential negative effects on bone health, renal function and cardiovascular health.
Early concerns that increased levels of calcium excretion associated with a high protein diet may have a deleterious effect on bone health appear to be unfounded with recent study data comparing the effect of high or low protein diets in postmenopausal women indicating that additional calcium excreted is offset by increased intestinal calcium absorption, particularly when animal protein is consumed.  No difference was seen in osteoclast or osteoblast activity irrespective of amount of dietary protein. This finding was reflected in a small 3-month RCT (n30) comparing subjects assigned to either a low-CHO (20 g CHO/day rising to 40 g/day in months two and three) or unrestricted diet.  A 2011 review of the effect of protein on bone health concluded that a high protein diet should not be followed without "adequate intake of calcium, fruit and vegetables." 
It is commonly accepted that a high protein diet may be damaging to kidney function and patients with CKD are advised not to follow the AD.  In 2012, analysis of a long-term (24-month) parallel RCT found that there was no difference in kidney function in obese but otherwise healthy subjects following a low-CHO high protein diet compared to matched controls who followed a low-fat diet.  This opinion was reflected by the report to the Nutrition Society with the qualification that those with diabetes or pre-existing kidney disease should be cautious of high-protein diets. 
Despite concerns that a diet that is low in CHO and high in protein and fat may have a detrimental effect on cardiovascular health, a number of studies have found that such diets may actually have a positive effect by reducing triglycerides , while potentially lowering low-density lipoprotein cholesterol (LDL-C) and blood pressure and raising high-density lipoprotein cholesterol (HDL-C). 
| Conclusion|| |
Despite its widespread popularity, the AD continues to court controversy and there remains a requirement for high-quality RCTs to establish its long-term benefits and side effects.
| Reflections|| |
On the face of it, the Atkins Diet appears to offer an effective method of weight loss compared to other weight loss programs. The macronutrient composition of the diet, however, remains controversial and low fruit and vegetable consumption has been identified by the World Health Organization as a key risk factor in global mortality.  It is important to remember that over the long term, a conventional high-CHO/low fat diet can lead to similar weight loss without the unpleasant side effects induced by ketosis while including fruit and vegetables which, due to their evidence-based health benefits, are acknowledged globally as an essential element of healthy nutrition.
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