the fad diet promise | rapid weight loss | fad diet promise is very alluring, rapid weight loss!  Sounds like a magic pill right?  But at what cost?  And how long does the “high” last?

Are Low Carb, High Protein Diets all that they claim?  When I was in my final year studying nutrition in 2005 I reviewed the evidence on one of the earlier models of the low carb, high protein diet, then the popular version was the Atkins diet to see what the science says.  New versions of this diet pop up with other names… but I would argue the evidence hasn’t changed that much.

Here is what we knew over a decade ago… not much has changed…

The growing incidence of obesity is a major public health concern, particularly because of the associated health risks i.e. heart disease, stroke and Type II diabetes.

In light of this the claims made by Dr Atkins, a cardiologist, seem somewhat appealing… (despite the fact he was overweight himself and had heart disease when he died).  He offered a diet that “lets you lose weight without counting calories, makes you feel and look better, naturally re-energizes you, keeps lost pounds off forever with a new lifetime nutritional approach that includes rich delicious food.”  He also claimed that the diet promoted good health and disease prevention (Atkins, 2003; Astrup, Larsen & Harper, 2004).

But how realistic and feasible is this from an informed perspective.  His diet may indeed be an effective tool for weight loss which may benefit obese patients but at what cost?  There is much controversy over his claims and the health and safety of high protein, low carbohydrate diets.  Primarily because many of the claims lack scientific evidence and research and directly contradict leading expert opinion in what constitutes optimum nutrition and disease prevention.

Several randomised controlled trials compared high carbohydrate diets with other popular diets (Yancy et al, 2004; Stern et al, 2004; Brehm et al, 2003 & Foster et al, 2003, Sahama et al, 2003 cited in Riley et al, 2004 & Astrup et al, 2004),  and found evidence that low carbohydrate diets might offer greater weight loss in the short term (over 3-6 months), however they do not offer better weight control than other lower fat, higher carbohydrate diets in the long term. (Riley et al, 2004; Astrup et al, 2004; Stern et al, 2004; Foster et al, 2003).

Atkins claimed that the weight loss and ability to eat unlimited calories was due to a metabolic advantage, which accounted for his claim of weight loss without counting calories.  However there is no evidence that the high fat, high protein diet is particularly thermogenic, fat has a low thermogenic effect, and although a high protein diet might increase 24 hr energy expenditure by 2-3% (Mikkelson, 2000), such an effect cannot account for more than a small fraction of the observed weight loss ( Astrup et al, 2004).  We also know that the body typically will adjust for calorie consumption and so people did not tend to eat more calories yet miraculously lose weight.

A study conducted by the North American Association for the Study of Obesity showed that Atkins dieters cut their normal daily caloric intake by 1000 calories.  Furthermore, in the research study presented in The Annals of Internal Medicine, scientists found that in both the low fat diet group and in the Atkins diet group, calorie consumption was reduced compared to the participant’s previous diets.  Thus suggesting that restricting calories is what causes weight loss, therefore while Atkins dieters can supposedly eat unlimited calories, they tend not to (The Atkins Diet: A Comprehensive Review, 15/03/2005).

A systematic review of low carbohydrate diets reported that the weight loss is associated with only the duration of the diet and the restriction of energy intake, not with carbohydrate restriction itself (Freedman et al, 2001 cited in Astrup et al, 2004). Weight loss on the low- carbohydrate diet is probably caused by a combination of restriction of food choices and the enhanced satiety produced by the high protein content (Astrup et al, 2004). (The reader is referred to Porrini et al, 1997 & Skov et al, 1999, cited in Astrup et al, 2004).

(Two important points here worth expanding:  1.  Long term restriction is unsustainable, so despite it working in the short term the body will ultimately readjust, either by slowing down it’s metabolism or by increasing consumption eventually.  2. This information about how protein influences satiety is useful when used wisely, for example in helping people understand the role of protein in obtaining satiety, and also in blood sugar control. Practically applied: eat some protein with your carbs.)

The Atkins diet (or new diets modelled off these principles – low carb and mod to high protein) encourages consumption of protein (in some cases in undefined or unlimited amounts) and high fat foods and discourages consumption of many fruits, starchy vegetables, and whole grain breads and cereals.  Restricted intake of these foods is not commendable with long term nutritional adequacy, and would be lower in fiber and other plant nutrients (phytonutrients) and may pose a second-line increased risk of heart disease and cancer (Astrup et al, 2004). There are a number of reasons why this diet does not promote good health and disease prevention as claimed.  Weight loss on it’s own is not a predictor of improved health.

Independent of the effects of obesity, meat consumption has been related to an increased risk of CVD (Gregor, 2004).  The American Heart Association voiced its concerns over the associated health risk of high protein diets.  Furthermore the diet doesn’t distinguish much between good protein and harmful sources, and good fats and harmful fats.  High protein animal foods are usually also high in saturated fat.  When these foods are fried, chargrilled or highly processed (bacon, cold meats, sausages) they can be harmful for the body. There is strong scientific evidence that a diet high in unhealthy fats or processed meats are bad for ones health as it increases the risk of heart disease, stroke and increases risk of cancer and diabetes (AHA, 2002; Gregor, 2004) (Kazaks et al, 2003; Gregor, 2004) (World Cancer Research Fund; American Institute for Cancer Research, 1997, cited in Gregor, 2004) .  The Food Standards Agency (2005) shared this concern that low carbohydrate diets tend to be high in fat, but this might not be the only concern.  The WHO has also expressed concerns over the risks of eating too much red meat and processed meat.

The Food Standards Agency’s advice is to eat a healthy balanced diet, which should include carbohydrates to make up a third of the food eaten (FSA, 2003).  This is supported by the Mayo Clinic and other authorities.  They warn that cutting out starchy foods, can be bad for one’s health because one could be missing out on a range of nutrients.    Strictly limiting carbohydrates reduces intake of plant based foods rich in phytochemicals, bioflavanoids, carotenoids and other micronutrients now regarded as important in a healthy diet (Ornish, 2004).  Of course, not all carbs are created equal… and the research supports plants, vegetables, fresh fruit and some whole grains like oats, quinoa, sorghum and millet.

Recommendations of the American Cancer Society are to include fruit and vegetables at every meal and as snacks to ensure five (or more) servings a day are eaten.  They recommend consumption of whole grains in preference to refined carbohydrates and they recommend that red meat consumption is limited, particularly if high in fat.  The restrictions imposed by the Atkins diet make it impossible to comply with these guidelines, the daily carbohydrate allowance is simply too low (The Atkins Diet: A Comprehensive Review, 15/03/2005).  While the Atkins plan promotes the use of supplements, all these important phytochemicals are simply not available in a pill.  Furthermore a diet that relies on supplementation to meet nutritional needs cannot be seen to be best practice or balanced, and diminishes its credibility as “a lifetime nutritional approach”.  Sure, there is evidence that many of us will need to supplement with vitamins and minerals to achieve optimal health at different seasons of our lives, for different reasons, yet at the same time if we eat wisely, and in sustainable ways,  it is possible to be well nourished without relying on supplements.

In addition to all these concerns excess protein may lead to an increased risk of kidney and liver disorders, and osteoporosis (AHA, 2005).  A high animal protein diet can result in a build up of sulphuric acid in the body.  The body must then neutralise this to maintain proper internal pH balance.  The body tries to buffer the sulphuric acid load with calcium which it leaches out of the bones.  There are two consequences to this, people on high meat diets can lose so much calcium in the urine that it can solidify into kidney stones and secondly, over time, enough calcium may be lost to increase risk of osteoporosis (Gregor, 2004).  (For further information the reader is referred to Reddy et al, 2002).

Eskimos experienced the world’s highest rate of osteoporosis, despite ingesting at least 2000 milligrams of calcium daily from fish bones.  Their extremely high protein intake caused bone calcium loss (Stefansson, 1936 cited in Matesz, 2004).  (We consider some of this poor calcium utilisation may also be partly because of the lack of vitamin D available from the sun.) However as, primitive Eskimos obtained 90% of their calories from meat and fat from: seals, whales, caribou and fish, available research may provide the best data on the potential long term effects of high protein and high fat diets (Matesz, 2004).  (The reader is referred to Bjerregaard & Dyerberg, 1988 and Kromman & Green, 1950-1974 and Mazess, 1974).

Clearly there are concerns about the long term effects of a high protein, low carbohydrate diet. The current guidelines for best health practice, based on available evidence, emphasize a healthy diet rich in fruits, vegetables, whole grains, lean meats, fish and poultry, and low fat dairy products accompanied with a good exercise regime (AHA, 2005; FSA, 2005).   While the Atkin’s diet may result in weight loss, it doesn’t teach people to adopt good lifestyle choices or encourage basic weight management strategies like portion control and serving sizes, let alone develop the skills necessary for a lifetime of balanced nutrition (AHA, 2005).

Sure, low fat diets are not the answer either, and absolutely a diet in high refined carbs is going to make you gain weight and probably unhealthy.

The answer is the same in my opinion as it has been for years.

Probably Michael Pollan says it best: “Eat food.  Not too Much. Mostly Plants.”  The problem is many people are confused about one simple fact:

What is food?  And we could solve a whole bunch of problems if we focused less on the ideal macronutrient ratios and more on the art of eating real food.

So expanding on simple truths:  No one macronutrient is to blame.  You don’t have to cut out carbs, but you do need to be carb smart.  You don’t need to cut out fat, but you do need to know the difference between good and bad fats and listen to your body when you are consuming them, and you certainly don’t need to eat copious amounts of animal protein to build muscle or become lean.

Here are some simple ideas that work:  Eat foods most closely resembling their natural form, organic where possible.  Eat plants everyday and animals occasionally.  Stop when you are 80 percent full.  Eat to nourish most of the time.  Eat for your psychology (treat, reward, comfort, pleasure, etc.) only 20 per cent of the time.  Chew, eat slowly, be present when eating.  Eat sitting down, with friends or family.  Plan your eating, take care with your eating, and create rituals and routines around nourishing your body.

Rather than getting your guidance from the latest fad, look to the people living well and into their hundreds for inspiration…  (Read books like The China Study or Whole… or follow authors like Westin Price, Michael Pollan, Patrick Holford and Campbell.)

And people certainly aren’t asking this question enough… which is what I base my whole program around:  What is driving behavior?!!

what drives behaviour |

Reference List:

American Heart Association: Media Advisory, 22/07/2002

As retrieved on 28/03/2005

American Heart Association: Media Advisory: American Heart Association Statement of High Protein, Low carbohydrate Diet Study Presented at Scientific Sessions, 19/11/2002

As retrieved on 28/03/2005

Astrup, A., Larsen, T., & Harper, A. Atkins and other low carbohydrate diets: hoax or an effective tool for weight loss? The Lancet, Sept 2004, Vol 364, 9437.

Bjerregaard, P., Dyerberg, J. Mortality from ischaemic heart disease and cerebrovascular disease in Greenland.  International Journal of Epidemiology, September 1988; 17 (3)

Bravata, D., Sanders, L, Huang, J., Krumholz, H., Olkin, I., Gardner, C. & Bravata, D. (2003). Efficacy and Safety of Low- Carbohydrate Diets: A Systematic Review. JAMA, Vol 289, 14.

Dansinger, M., Gleason, J., Griffith, J., Selker, H., & Schaefer, E. (2005).  Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial. JAMA, 5; 293, 1.

FAO, 1998.  Carbohydrates in Human Nutrition (FAO Food and Nutrition Paper-66)

As retrieved on 28/03/2005

Feinman, R., & Fine, E. (2004).  A “calorie is a calorie” violates the second law of thermodynamics.  Nutrition Journal, Vol 3, 9.

Food Standards Agency

As retrieved from web on 05/04/2005

Gregor, M. Atkins Facts. Latest in Human Nutrition, June 2004, Vol 2, 6.

As retrieved from web on 28/03/2005

High-Protein Diets, American Heart Association

As retrieved on 28/03/2005

Kazaks, A. & Stern, J. (2003).  Obesity Treatments and Controversies. Diabetes Spectrum, 16

Retrieved on 31/03/2005

Kromann, N. & Green, A. Epidemiological studies in the Upernavik district, Greenland.  Incidence in some chronic diseases, 1950-1974. Acta Med Scan 1980; 208 (5)

Matesz, D. Nutrition and Wellness.  Acupuncture Today, November 2004, Volume 5, 11

Mazess, R. Bone mineral content of North Alaskan Eskimos.  American Journal of Clinical Nutrition 1974; 27

Peters, S. & LeBlanc, P. (2004).  Metabolic aspects of low carbohydrate diets and exercise. Nutr Metab (Lond), 1, 7

Reddy, S., Wang, C., Sakhaee, K., Brinkley, L. & Pak, C. Effect of low carbohydrate high protein diets on acid-base balance, stone-forming propensity, and calcium metabolism.  The American Journal of Kidney Diseases, August 2002,Vol 40, 2.

Riley, M. & Coveney, J. (2004). Atkins and the new diet revolution: is it really time for regimen change? MJA; 181, 10

The Atkins Diet- A Comprehensive Analysis

As retrieved from the web on 15/03/2005

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Posted on Apr 12, 2016 - Last updated on Apr 12, 2016

About the Author

Lisa Cutforth is the founder of Size Fantastic. A nutritionist and foodie with a degree in Nutrition with Psychology and a passion for health, Lisa’s ambition is to take health off the “too hard” shelf and restore her clients confidence in themselves and their ability to heal and be well… Size Fantastic to us means: looking and feeling great, inside and out!