1. Atkins’ Diet: Does it REALLY Work? Dr. Christine Simpson, MD FRCPC General Internal Medicine CHIP Director, Edmonton

2. Who? Dr. Atkins, cardiologist Dr. Atkins, cardiologist Sold 10 million copies of his book, Sold 10 million copies of his book, “Diet Revolution”, copyrighted 1973 “Diet Revolution”, copyrighted 1973 Other contemporaries: Other contemporaries: –“The Zone”, by Sears –“Protein Power”, by Eades

3. Why? Obesity epidemic began in the late 70’s Obesity epidemic began in the late 70’s Continual spiral upwards, despite the Continual spiral upwards, despite the low-fat dietary messages promoted by the medical profession 60% Americans overweight (BMI >25), 60% Americans overweight (BMI >25), 30% are obese (BMI >30) 30% are obese (BMI >30)

4. What? During the 1970’s, new concepts about fat During the 1970’s, new concepts about fat * primary nutritional evil * primary nutritional evil * especially saturated fat of meat & dairy * especially saturated fat of meat & dairy Atkins countered this by promising weight Atkins countered this by promising weight loss while eating steak, eggs and butter to loss while eating steak, eggs and butter to our heart’s content BECAUSE: our heart’s content BECAUSE: * carbs cause obesity and heart disease

5. Atkins’ motto: FAT IS HARMLESS!!! FAT IS HARMLESS!!!

6. One follower says of the diet: Atkins allowed his readers to eat “truly luxurious foods without limit,” as he put it, “lobster with butter sauce, steak with bearnaise sauce…bacon cheeseburgers,” but allowed no starches or refined carbohydrates, which means no sugars or anything made from flour. Atkins banned even fruit juices, and permitted only a modicum of vegetables, although the latter were negotiable, as diet progressed. Atkins allowed his readers to eat “truly luxurious foods without limit,” as he put it, “lobster with butter sauce, steak with bearnaise sauce…bacon cheeseburgers,” but allowed no starches or refined carbohydrates, which means no sugars or anything made from flour. Atkins banned even fruit juices, and permitted only a modicum of vegetables, although the latter were negotiable, as diet progressed. Garry Taubes

7. How? High glycemic index foods (carbs that are High glycemic index foods (carbs that are absorbed quickly) promote hyperglycemia ….an insulin surge…..then hypoglycemia This leads to hunger and MORE carbs This leads to hunger and MORE carbs carvings; hence, increased caloric intake During the insulin surge, sugar is During the insulin surge, sugar is transformed into FAT and muscle

8. The hypothesis: With a carb-depleted diet, there are NO With a carb-depleted diet, there are NO insulin surges When cellular glucose is depleted, fat and muscle metabolism (break-down) begins When cellular glucose is depleted, fat and muscle metabolism (break-down) begins This is the process called “ketosis”, which is identical to that seen in starvation This is the process called “ketosis”, which is identical to that seen in starvation

9. Is there any scientific evidence? Up until 2002, virtually nothing Up until 2002, virtually nothing Most “evidence” was anecdotal Most “evidence” was anecdotal The best scientific evidence requires: The best scientific evidence requires: * a randomized, controlled trial testing two groups of subjects: testing two groups of subjects: a) Atkins diet versus b) high carb diet * Must look for benefits AND harm over time!

10. Two recent scientific studies: July 2002, American Journal of Medicine July 2002, American Journal of Medicine May 2003, New England Journal May 2003, New England Journal of Medicine Funded by the National Institute of Health Funded by the National Institute of Health

11. The Details: 132 people, average weight 286 pounds 132 people, average weight 286 pounds 63 people, average weight 217 pounds 63 people, average weight 217 pounds Low carb (25-30 g/day, ~100-120 Cal) Low carb (25-30 g/day, ~100-120 Cal) High carb (200-300 g/day, ~1200 Cal, High carb (200-300 g/day, ~1200 Cal, 25% fat) Followed for ONLY one year!

12. The Results: Low carb: Low carb: –1) in 6 months, lost 13 pounds - 2) in 6 months, lost 15 pounds; regained 1/3 - HDL increased by 18% -Trigs decreased by 28% -No diff in LDL or BP High carb High carb –1) in 6 months, lost 4 pounds - 2) in 6 months, lost 7 pounds; regained 1/5 - HDL increased by 3% -Trigs increased by 1% -No diff in LDL or BP

13. The Conclusion: A carb-depleted diet results in greater A carb-depleted diet results in greater weight loss in 6 months, and does not cause significant harm to the lipid profile (perhaps even a benefit?). ie. “A healthy, short-term method for ie. “A healthy, short-term method for weight loss!”

14. ????????????????????????????????? Does that really make sense? Does that really make sense?

15. Studies are inherently flawed! Flawed in design and interpretation Flawed in design and interpretation Very low sample size, very short-term Very low sample size, very short-term 40% drop-out rate (same in both groups) 40% drop-out rate (same in both groups)

16. What we were NOT told: Carb-eaters caught up with weight loss during the 2 nd 6 months Carb-eaters caught up with weight loss during the 2 nd 6 months Diet compositions were actually NOT Diet compositions were actually NOT drastically different: * 41% (Atkins) fat versus 33% * Dean Ornish says: “they have compared two diets, neither of which is very effective” “they have compared two diets, neither of which is very effective”

17. An even closer look: Most of the weight lost in the Atkins diet Most of the weight lost in the Atkins diet group was due to a decreased total amount of consumed calories! The initial weight loss is water, followed The initial weight loss is water, followed by fat AND muscle; is ketosis dangerous? The lipid profile changes can not be The lipid profile changes can not be considered secondary to diet compositions

18. One more point: Ketosis theory and blood sugar/insulin Ketosis theory and blood sugar/insulin surge mechanism: - NOT true when whole grains, legumes, and high-fiber fruits and vegetables are consumed “Foods as grown, simply prepared!”

19. The REAL scientific conclusion: “longer and larger studies are required “longer and larger studies are required to determine the long-term safety and efficacy of low-carbohydrate, high-protein, high-fat diets.” The debate continues, but the studies to date do NOT prove superiority of an Atkins-style diet over a high COMPLEX carbohydrate diet; The debate continues, but the studies to date do NOT prove superiority of an Atkins-style diet over a high COMPLEX carbohydrate diet; Rather, they simply re-emphasize that calorie restriction aids in short-term weight loss. Rather, they simply re-emphasize that calorie restriction aids in short-term weight loss.

20. Any volunteers for further studies? Questions? Questions? Comments? Comments?

22. Point 1: Save a quarter on your food bill… Save a quarter on your food bill… …and add 10 years to your life! …and add 10 years to your life!

23. Point 2: Don’t tell them it’s healthy… Don’t tell them it’s healthy… …tell them it’s cheap! …tell them it’s cheap!