Effects of a
Low Carbohydrate Diet

Effects of a Low Carbohydrate Diet: Overview

No matter what Atkins or other diet books tell you, the balance of evidence clearly shows that saturated animal fat is bad for you and is associated with increased risk of cancer [Journal of the National Cancer Institute 95 (2003): p.1079], diabetes, and heart disease. [WHO Technical Report Series 916, 2003]  Even independent of the effects on obesity, meat consumption itself has been related to increased risk of coronary heart disease [Preventive Medicine 13 (1984): p.490] and for over 40 years medical reviews have also shown the detrimental impact of dietary cholesterol consumption. [Geriatrics (1961): p.407]

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The Chair of the American Medical Association's Council on Food and Nutrition explained in testimony before Congress why the AMA felt they had to formally publish an official condemnation of the Atkins Diet: "It became apparent that the (Atkins) diet as recommended poses a serious threat to health."  "People need to wake up to the reality," Former U.S. Surgeon General C. Everett Koop writes, that the Atkins Diet is "unhealthy and can be dangerous." [Shape Up America!  news release, 29 December 2003]

The largest organization of food and nutrition professionals in the world calls the Atkins Diet "a nightmare of a diet." [Journal of the American Dietetic Association 102 (2002): p.260]  The official spokesperson elaborated: "The Atkins Diet and its ilk – any eating regimen that encourages gorging on bacon, cream and butter while shunning apples, all in the name of weight loss – are a dietitian's nightmare."  The ADA has been warning Americans about the potential hazards of the Atkins Diet for almost 30 years now. [Journal of the American Dietetic Association 66 (1975): p.277]

The National Academy of Sciences, the most prestigious scientific body in the United States, agrees with the AMA and the ADA in opposing the Atkins Diet.  So does the American Cancer Society. [American Cancer Society. Weighing In on low carb Diets, 2004]  And the American Heart Association. [Circulation 104 (2001): p.1869]  And the Cleveland Clinic [The Cleveland Clinic. High Protein, Low Carbohydrate Diets, August 2003], and Johns Hopkins [Diabetes 2004. Johns Hopkins University White Paper, 2004], and the American Kidney Fund [American Kidney Fund news release, 25 April 2002], and the American College of Sports Medicine [Medicine and Science in Sports and Exercise 33 (2001): p.2145], and the National Institutes of Health [NIH Publ. No. 94-3700, 1993].

In fact there does not seem to be a single major governmental or nonprofit medical, nutrition or science-based organization in the world that supports the Atkins Diet. [Circulation 104 (2001): p.1869]  As a 2004 medical journal review concluded, the Atkins Diet "runs counter to all the current evidence-based dietary recommendations." [Journal of the American College of Cardiology 43 (2004): p.725]

A 2003 review of the safety of low carbohydrate diets reeled off an alarming list of potential problems: "Complications such as heart arrhythmias, cardiac contractile function impairment, sudden death, osteoporosis, kidney damage, increased cancer risk, impairment of physical activity and lipid [cholesterol] abnormalities can all be linked to long-term restriction of carbohydrates in the diet." [Asia Pacific Journal Clinical Nutrition, 12: pp. 396-404 (2003)]

Weight Loss
This being the main objective of any diet, it is interesting to note that even if people can handle the side-effects of the diet, there are no data to show that the initial rapid weight loss on diets such as the Atkins Diet can be maintained long term.  Many of the studies on the Atkins Diet have lasted only a few days [Journal of the American Medical Association 289 (2003): p.1837]; the longest the Atkins Diet has ever been studied is one year.

There have been 3 such year-long studies and not a single one showed significantly more weight lost at the end of the year on the Atkins Diet than on the control diets.  In the year-long comparison of the Atkins Diet to Dean Ornish's vegetarian diet, Weight Watchers, and The Zone Diet, the Atkins Diet came last in terms of weight lost at the end of the year.  Ornish's near-vegan diet seemed to show the most weight loss. [Dansinger, M.L., Gleason, J. L., Griffith, J.L., et al., "One Year Effectiveness of the Atkins, Ornish, Weight Watchers, and Zone Diets in Decreasing Body Weight and Heart Disease Risk", Presented at the American Heart Association Scientific Sessions November 12, 2003 in Orlando, Florida.]

The most formal study of lasting weight loss is the highly respected National Weight Control Registry, funded by the National Institutes of Health (NIH).  For over 10 years, the Registry has tracked the habits of thousands of successful dieters.  They now have 5,000 Americans confirmed to have lost an average of 70 pounds and able to prove they have kept it off for at least 6 years.  After a decade of rigorously tracking those who most successfully lost weight – and kept it off – one of the chief investigators told everyone in an interview what they found: "Almost nobody's on a low carbohydrate diet." [Reason, March 2003]

These researchers, led by a team at Brown and the University of Colorado, found that the people most successful in losing and maintaining their weight were eating high carbohydrate diets – five times as many carbs as Atkins proscribes in the "weight loss" phase of his diet [American Journal of Clinical Nutrition 66 (1997): p.239].  Out of the thousands of people in the National Weight Control Registry, fewer than 1% follow a diet similar to the Atkins program.  "We can't find more than a handful of people who follow the Atkins program in the registry," said one chief investigator, "and, believe me, we've tried." [The Washington Post, 27 August 2002]

We burn fat all the time; it's only when one is carbohydrate deficient and has to burn fat ineffectively that one goes into a state of ketosis – when you have so much acetone in your blood that it noticeably spills out into your lungs, or so many other ketones that they spill out into your urine.

In biochemistry class, doctors learn that fat "burns in the flame of carbohydrate."  When you're eating enough carbohydrates, fat can be completely broken down as well.  But when your body runs out of carb fuel to burn, your body's only choice is to burn fat inefficiently using a pathway that produces toxic byproducts like acetone and other ketones.

Symptoms of ketosis include general tiredness, abrupt or gradually increasing weakness, dizziness, headaches, confusion, abdominal pain, irritability, nausea and vomiting, sleep problems and bad breath. [Cleveland Clinic Journal of Medicine 68(2001): p.761]

In World War II, the Canadian Army had an illuminating experience with ketogenic diets.  For emergency rations, infantry troops had pemmican, which is basically a carbohydrate-free mixture of beef jerky and suet (animal fat).  The performance of the infantrymen forced to live off pemmican deteriorated so rapidly, they incapacitate them in a matter of days.  As reported in the journal War Medicine in 1945, "On the morning of the fourth day of the diet, physical examination revealed a group of listless, dehydrated men with drawn faces and sunken eyeballs, whose breath smelled strongly of acetone." [War Medicine 7 (1945): p.345]

A ketogenic diet, concluded one medical review, "can be associated with significant toxicity." [Epilepsia 39 (1998): p.744]

In Contrast...
Every single long-term prospective cohort study ever performed on the foods that diets such as Atkins' restrict – fruits, vegetables, nuts and whole grains – show that they protect people from the nations' biggest killer: heart disease. [Journal of the American Medical Association 288(2002):2569]

Harvard studied 75,000 women for a decade and the results suggest that the more whole grains people eat – like brown rice and whole wheat bread – the lower their risk of having a heart attack. [American Journal of Clinical Nutrition 70 (1999): p.412]  Harvard studied 40,000 men for a decade and suggested that eating whole grains may cut one's risk of developing diabetes by more than half. [American Journal of Clinical Nutrition 76 (2002): p.535]

>> For more information, including the latest news on this subject, visit AtkinsExposed.org.

Signs, symptoms & indicators of Effects of a Low Carbohydrate Diet:

Symptoms - Abdomen

Symptoms - Bowel Movements

Occasional/frequent/constant bowel movement changes

In a study funded by Dr. Atkins himself, 70% of the people that could stick with the diet lost the ability to have a normal bowel movement.  The May 2004 Annals of Internal Medicine study showed that most of the Atkins Dieters had significantly more diarrhea, general weakness, rashes and muscle cramps.

Symptoms - Cardiovascular

Symptoms - Gas-Int - General

Symptoms - Mind - Emotional

Being/being very easily irritated

Not only may diets such as the Atkins Diet impair mental functioning, they may impair emotional functioning as well.  Researchers at MIT are afraid the Atkins Diet is likely to make many people – especially women – irritable and depressed. [MIT News, 20 February 2004]

Symptoms - Mind - General

Reduced/poor mental clarity

Experts have voiced a longstanding concern that ketosis might fog up people's thinking, but it took until 1995 to be formally tested.  As reported in the International Journal of Obesity article "Cognitive Effects of Ketogenic Weight-Reducing Diets," researchers randomized people to either a ketogenic or a nonketogenic weight loss diet.  Although both groups lost the same amount of weight, those on the ketogenic diet suffered a significant drop in cognitive performance.  After one week in ketosis, higher order mental processing and mental flexibility significantly worsened into what the researcher called a "modest neuropsychological impairment." [International Journal of Obesity 19 (1995): p.811]

Symptoms - Skin - Conditions

Regular/frequent rashes

The May 2004 Annals of Internal Medicine study showed that most of the Atkins Dieters had significantly more rashes than the general population.

Symptoms - Sleep

Conditions that suggest Effects of a Low Carbohydrate Diet:


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Risk factors for Effects of a Low Carbohydrate Diet:

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Symptoms - Food - General

Short-term/long-term low-carb dieting

The American Heart Association states: "Individuals who follow these diets are therefore at risk for compromised vitamin and mineral intake, as well as potential cardiac, renal, bone, and liver abnormalities overall." [Circulation 104 (2001): p.1869]


Effects of a Low Carbohydrate Diet can lead to:



Authorities recommend that Americans get "at least 30-35 grams" [Gastroenterology 118 (2000): p.1233] of fiber each day "from foods, not from supplements." [Circulation. 102 (2000): p.2284]  The initial phase of Atkins' diet, which dieters may have to repeatedly return to, has about 2gm of fiber per day. [Atkins, RC. Dr. Atkins New Diet Revolution. Avon Books, 1999]

The May 2004 Annals of Internal Medicine study showed once again that most of the Atkins Dieters are constipated and headachy.

Bad Breath (Halitosis)

The acetone resulting from a state of ketosis escapes through the lungs – giving Atkins Diet followers, for example, what one weight-loss expert calls "rotten-apple breath." [Health 19 (1996): p.102]  The other ketones have to be excreted by the kidneys.  In a study funded by Dr. Atkins himself, most of the people that could stick with the diet reported headaches and halitosis (bad breath).



The director of MIT's distinguished Clinical Research Center measured the serotonin levels in the brains of 100 volunteers eating different diets.  Serotonin is a chemical messenger in the human brain that regulates mood.  In fact, the way antidepressants like Prozac are purported to work is by increasing brain levels of serotonin.

What the MIT researchers found is that the brain only made serotonin after a person ate carbohydrates.  Carbohydrates seemed to naturally stimulate serotonin.  By starving of the brain of this essential mood elevator, the researchers fear that diets such as the Atkins Diet may make people restless, irritable or depressed.  Women, people under stress, and those taking anti-depressants may be most at risk. [MIT News 20 February 2004]


Excessive Fatigue

One study found that all those subjected to carb-free diet complained of fatigue after just two days.  "This complaint was characterized by a feeling of physical lack of energy... The subjects all felt that they did not have sufficient energy to continue normal activity after the third day.  This fatigue promptly disappeared after the addition of carbohydrate to the diet." [Arch Internal med 112(1963): p.333]


General Weakness

Gradually increasing weakness is a sign of ketosis.  The May 2004 Annals of Internal Medicine study showed that most of the Atkins Dieters suffered significantly more general weakness.

Gout / Hyperuricemia

In March 2004, an article was published in the New England Journal of Medicine documenting the effect of meat intake on gout risk.  Harvard researchers followed almost 50,000 men for 12 years and found that "each additional daily serving of meat was associated with a 21% increase in the risk of gout."  In fact, the Atkins Diet has been blamed directly for the rising incidence of this painful disease. [The Observer, 18 January 2004]

Muscle Cramps / Twitching

The May 2004 Annals of Internal Medicine study showed that most of the Atkins Dieters had significantly more muscle cramps than the general population.  Along with the toxins created by low-carbohydrate diets, one's kidneys also flush out critical electrolytes such as calcium, magnesium and potassium, which may result in muscle cramps or worse. [Asia Pacific Journal of Clinical Nutrition 12 (2002): p.396]


Male Hair Loss

Hair loss is a common side-effect of low-carb diets.  A study funded by Dr. Atkins himself found that about 10% suffered from hair loss.  The precise cause is unknown at the time of writing: it may be due to basic malnutrition, or, as one of our doctors notes, "I've seen this over and over again in my practice.  Basically, this diet can cause your cortisol levels to go sky high, which will lead to hair loss.  Ideally, you should change your diet to help solve this problem."

Recommendations for Effects of a Low Carbohydrate Diet:


Increased Fruit/Vegetable Consumption

Fruit consumption alone has been linked to lower rates of numerous cancers [Cancer Causes and Control 7 (1996): p.178] and may reduce heart disease mortality, cancer and even total mortality. [British Medical Journal 313 (1996): p.775]  The World Health Organization blames low fruit and vegetable consumption on literally millions of deaths worldwide. [World Health Organization. Fruit, vegetables and NCD prevention]  Everyone should eat more fruits and vegetables as if their lives depended on it.

Animal/Saturated Fats Avoidance

The best dietary strategy to reduce one's risk of dying from the number 1 killer in the U.S. is to reduce one's consumption of saturated fat and cholesterol.  The evidence backing this, according to the American Heart Association, is "overwhelming." [Circulation 98 (1998): p.935]

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