Why Low Carb? Why high fat?

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Introduction

LCHF compares favorably to low calorie for improvement in cardiovascular1,2,3,4 and renal health markers.5 While Diabetes Canada emphasizes calorie restriction and increased physical activity6, Feinman et al. argue LCHF treats the root cause of insulin resistance and should be first line.7,8

Why Low Carb?

1. The “nutritional ketosis” induced by the LCHF dietary pattern suppress appetite, facilitating decreased caloric intake and weight loss9,10
2. Compared to low fat, Ghrelin levels are lower and energy expenditure is greater on a low carb weight loss maintenance program11
3. Studie with 2 years of follow-up show modest ongoing benefit12,13,14,15
4. “The lower limit of dietary carbohydrate compatible with life is zero, provided that adequate amounts of protein and fat are consumed.”16
5. Nutritional ketosis is not harmful and not the same as ketoacidosis17
6. Regardless of degree of glycemic control, insulin resistance is associated with      cardiovascular disease18
7. Sugar, not salt, causes the hypertension associated with metabolic syndrome; we are worried about “The wrong white crystals”19,20

Why High Fat?

1. Dietary fat restriction has not been proven to reduce cardiovascular risk21
2. Saturated fat consumption has not been proven to cause cardiovascular disease22,23
3. The American Heart Association disagrees. They concluded in 2017 that saturated fat intake should be minimized to reduce cardiovascular disease based on a meta-analysis of 4 RCTs, the most recent of which was published in 1983 and was conducted in a Finish hospital for patients with psychiatric illness.24
4. Replacing dietary fat with carbohydrate calories is associated with lower HDL, and higher serum triglycerides and small-dense LDL subfraction; this triad is called ‘atherogenic dyslipidemia’ and is associated with increased cardiovascular risk25
5. Systematic review and meta-analysis data finds that a low carb, high fat dietary pattern does not result in clinically signifcant increases in LDL in comparison to a low fat appraoch26
6. Carbohydrates, not dietary fat, increase serum triglycerides27
7. Serum triglycerides, HDL and small-dense LDL subfraction predict 5 year myocardial infarction risk but LDL-C does not; on the other hand, reduced LDL-C is a marker of treatment response to statin therapy and predicts myocardial infarction risk reduction28
8. Still concerned about LDL-C? LDL-C does NOT cause cardiovascular disease29
9. It is “oxidized small-dense LDL”, that is pathogenic for atherosclerosis, not LDL-C30

Selected Publications:

1. Moderate amounts of sugar are ignorantly permitted by the American Heart Association31
2. The World Health Organization continues to ague that obesity is a behavioral problem: exercise more and eat less32
3.  Moderate-intensity PA between 150 and 250 min per week will provide only modest weight loss33
4. Gastroesophageal reflux problems? Prescribe a low carb diet34
5. Hot flashes? Therapeutic trial of Folic acid 1 mg daily for 30 days35
6. Hair loss associated with weight loss? Therapeutic trial of Zinc 50 mg daily taken with food for 2 months36,37
7. To quote the words of pharmacist Sean McKelvey, IPTN CEO, "T2D remission is possible, even in a busy primary care practice"38

References:

1. Volek JS et al. Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids. 2009 Apr;44(4):297-309.
2. Volek JS et al. Effects of dietary carbohydrate restriction versus low-fat diet on flow-mediated dilation. Metabolism. 2009 Dec;58(12):1769-77.
3. Mayer SB et al. Two diets with different haemoglobin A1c and antiglycemic medication effects despite similar weight loss in type 2 diabetes. Diabetes Obes Metab. 2014 Jan;16(1):90-3.
4. McKenzie AL et al. A Novel Intervention Including Individualized Nutritional Recommendations Reduces Hemoglobin A1c Level, Medication Use, and Weight in Type 2 Diabetes. JMIR Diabetes. 2017 Mar 7;2(1):e5.
5. Tirosh A et al. Renal function following three distinct weight loss dietary strategies during 2 years of a randomized controlled trial. Diabetes Care. 2013 Aug;36(8):2225-32.
6. Sievenpiper JL et al. Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada: Nutrition Therapy. Can J Diabetes 2018;42(Suppl 1): p. S65.
7. Feinman RD et al. Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base. Nutrition. 2015 Jan;31(1):1-13.
8. Ludwig DS, Ebbeling CB. The Carbohydrate-Insulin Model of Obesity: Beyond      "Calories In, Calories Out". JAMA Intern Med. 2018 Aug 1;178(8):1098-1103.
9. Gibson AA et al. Do ketogenic diets really suppress appetite? A systematic review and meta-analysis. Obes Rev. 2015 Jan;16(1):64-76.
10. Ratliff J et al. Consuming eggs for breakfast influences plasma glucose and ghrelin, while reducing energy intake during the next 24 hours in adult men. Nutr Res. 2010 Feb;30(2):96-103.
11. Ebbeling CB et al. Effects of a low carbohydrate diet on energy expenditure during weight loss maintenance: randomized trial. BMJ. 2018 Nov 14;363:k4583.
12. Foster GD et al. Weight and metabolic outcomes after 2 years on a low-carbohydrate versus low-fat diet: a randomized trial. Ann Intern Med. 2010 Aug 3;153(3):147-57.
13. Guldbrand H et al. In type 2 diabetes, randomisation to advice to follow a low-carbohydrate diet transiently improves glycaemic control compared with advice to follow a low-fat diet producing a similar weight loss. Diabetologia. 2012 Aug;55(8):2118-27.
14. Iqbal N et al. Effects of a low-intensity intervention that prescribed a low-carbohydrate vs. a low-fat diet in obese, diabetic participants. Obesity. 2010 Sep;18(9):1733-8.
15. Athinarayanan SJ et al. Long-Term Effects of a Novel Continuous Remote Care Intervention Including Nutritional Ketosis for the Management of Type 2 Diabetes: A 2-year Non-randomized Clinical Trial.  Front Endocrinol (Lausanne). 2019 Jun 5;10:348. 
16. Institute of Medicine. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids. Washington, DC: National Academies Press; 2005. Chapter 6, Dietary carbohydrates: sugars and starches, Clinical effects of inadequate intake; p. 275.
17. Manninen AH. Metabolic Effects of the Very-Low-Carbohydrate Diets: Misunderstood      "Villains" of Human Metabolism. J Int Soc Sports Nutr. 2004; 1(2): 7–11.
18. Armstrong D, Stratton RD. Oxidative stress and antioxidant protection: the science of free radical biology and disease. New Jersey: John Wiley and Sons; 2016. Chapter 20, Metabolic syndrome, inflammation, and reactive oxygen species in children and adults; p. 328-338.
19. DiNicolantonio JJ, Lucan SC. The wrong white crystals: not salt but sugar as aetiological      in hypertension and cardiometabolicdisease. Open Heart. 2014 Nov 3;1(1).
20. O'Donnell M et al. Urinary sodium and potassium excretion, mortality, and      cardiovascular events. N Engl J Med. 2014 Aug 14;371(7):612-23.
21. Howard BV et al. Low-fat dietary pattern and risk of cardiovascular disease: the      Women's Health Initiative Randomized Controlled Dietary Modification Trial. JAMA. 2006 Feb 8;295(6):655-66.
22. de Souza RJ et al. Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies. BMJ. 2015 Aug 11;351.
23. Dehghan M et al. Associations of fats and carbohydrate intake with cardiovascular      disease and mortality in 18 countries from five continents (PURE): a prospective cohort study. Lancet. 2017 Nov 4;390(10107):2050-2062.
24. Sacks FM. Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association. Circulation. 2017 Jul 18;136(3):e1-e23.
25. Siri-Tarino PW et al. Saturated fats versus polyunsaturated fats versus carbohydrates      for cardiovascular disease prevention and treatment. Annu Rev Nutr. 2015;35:517-43.
26. Gjuladin-Hellon, T et al. Effects of carbohydrate-restricted diets on low-density lipoprotein cholesterol levels in overweight and obese adults: a systematic review and      meta-analysis. Nutr Rev. 2019 Mar 1;77(3):161-180. doi: 10.1093/nutrit/nuy049.
27. Volk BM et al. Effects of stepwise increases in dietary carbohydrate on circulating saturated Fatty acids and palmitoleic Acid in adults with metabolic syndrome. PLoS One. 2014 Nov 21;9(11).
28. Mora S et al. Atherogenic lipoprotein subfractions determined by ion mobility and first cardiovascular events after random allocation to high-intensity statin or placebo: the justification for the use of statins in prevention: an intervention trial evaluating rosuvastatin (jupiter) trial. Circulation. 2015 Dec 8;132(23).
29. Ravnskov U et al. LDL-C does not cause cardiovascular disease: a comprehensive review of the current literature. Expert Rev Clin Pharmacol. 2018 Oct;11(10):959-970. doi: 10.1080/17512433.2018.1519391. Epub 2018 Oct 11.
30. Griffin JE, Ojeda SR. Textbook of endocrine physiology, fourth edition. New York, New York: Oxford University Press; 2000. p. 404.
31. Johnson RK et al. Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association. Circulation. 2009 Sep 15;120(11):1011-20.
32. World Health Organization. Global strategy on diet, physical activity and health. 2004. Geneva, Switzerland. Retrieved from: http://www.who.int/dietphysicalactivity/strategy/eb11344/strategy_english_web.pdf on      November 1, 2017.
33. Donnelly JE et al. American College of Sports Medicine Position Stand. Appropriate physical activity intervention strategies for weight loss and prevention of weight regain for adults. Med Sci Sports Exerc. 2009 Jul;41(7):1532.
34. Pointer SD et al. Dietary carbohydrate intake, insulin resistance and gastro-oesophageal reflux disease: a pilot study in European- and African-American obese women. Aliment Pharmacol Ther. 2016 Nov;44(9):976-988. doi: 10.1111/apt.13784. Epub 2016 Sep 1.
35. Bani, S et al. The Effect of Folic Acid on Menopausal Hot Flashes: A Randomized      Clinical Trial. J Caring Sci. 2013 Jun; 2(2): 131–140. Published online 2013 Jun 1. doi: 10.5681/jcs.2013.016
36. Cheung EJ et al. Vitamin and Mineral Deficiencies in Patients With Telogen Effluvium: A Retrospective Cross-Sectional Study. J Drugs Dermatol. 2016 Oct 1;15(10):1235-1237.
37. Karashima T et al. Oral zinc therapy for zinc deficiency-related telogen effluvium. Dermatol Ther. 2012 Mar-Apr; 25(2):210-3.
38. Unwin D, Delon C, Unwin J, et al. What predicts drug-free type 2 diabetes remission? Insights from an 8-year general practice service evaluation of a lower carbohydrate diet with weight loss. BMJ Nutrition, Prevention & Health 2023;0:e000544. doi:10.1136/ bmjnph-2022-000544 

The Art and Science of Low Carbohydrate Living by Jeff Volek and Stephen Phinney

The Art and Science of Low Carbohydrate Performance by Jeff Volek and Stephen Phinney

The New Atkins for a New You by by Eric Westman, Stephen Phinney and Jeff Volek

The Institute for Personalized Therapetic Nutrition IPTN

The Canadian Clinicians for Therapeutic Nutrition CCTN

1. Is a low carb dietary pattern safe in the setting of chronic renal failure?

• My experience is that a low carb dietary pattern is safe provided that adequate time is spent counselling the patient NOT to over-consume protein. With strict advice not to consume more than 3 oz of meat up to 3 times per day, patients with chronic renal failure can achieve amelioration of makers of chronic renal failure including serum creatinine and urine microablumin:creatinine ratio. 

2. Is a low carb HIGH FAT dietary pattern appropriate for the patient with biliary colic?

• My is experience is that patients discharged from the emergency room are often advised by their general surgeon to follow a low fat dietary pattern to prevent exacerbation of biliary colic pain. And yet, my experience prescribing low carb HIGH FAT to patients with known cholelithiases is that this dietary pattern does NOT trigger attacks. It is suspected that a high fat dietary pattern can prevent gallstone formation during weight loss.