AUTHORITY NUTRITION

Randomized Controlled Trials in Nutrition

Written by Kris Gunnars, BSc on January 2, 2013

This is a collection of high quality research studies in nutrition, about some of the topics we cover on this website.

All of these studies are published in respected, peer-reviewed journals.

All of the studies on this page are randomized controlled trials in humans, unless otherwise noted.

Low-Carbohydrate vs. Low-Fat Diets

A low carb diet is based on foods that contain a low amount of carbohydrate. Foods that are high in sugars and starches are replaced with foods that are high in protein and fat.

A low fat diet, is based on foods that contain a low amount of fat, typically under 30% of total calories. Foods like fruits, vegetables and whole grains are emphasized.

The studies below are controlled trials where people are randomized to either a low-carb or a low-fat diet. The outcomes measured are usually body weight and risk factors for disease.

  1. Krebs NF, et al. J Pediatr. 2010 Aug;157(2):252-8.
  2. Hernandez, et al. Am J Clin Nutr March 2010 vol. 91 no. 3 578-585.
  3. Brinkworth GD, et al. Am J Clin Nutr. 2009 Jul;90(1):23-32.
  4. Volek JS, et al. Lipids. 2009 Apr;44(4):297-309.
  5. Tay J, et al. J Am Coll Cardiol. 2008 Jan 1;51(1):59-67.
  6. Keogh JB, et al. Am J Clin Nutr. 2008 Mar;87(3):567-76.
  7. Shai I, et al. N Engl J Med. 2008 Jul 17;359(3):229-41.
  8. Dyson PA, et al. Diabet Med. 2007 Dec;24(12):1430-5.
  9. Halyburton AK, et al. Am J Clin Nutr. 2007 Sep;86(3):580-7.
  10. Gardner CD, et al. JAMA. 2007 Mar 7;297(9):969-77.
  11. McClernon FJ, et al. Obesity (Silver Spring). 2007 Jan;15(1):182-7.
  12. Nickols-Richardson SM, et al. J Am Diet Assoc. 2005 Sep;105(9):1433-7.
  13. Meckling KA, et al. J Clin Endocrinol Metab. 2004 Jun;89(6):2717-23.
  14. JS Volek, et al. Nutr Metab (Lond). 2004; 1: 13.
  15. Yancy WS Jr, et al. Ann Intern Med. 2004 May 18;140(10):769-77.
  16. Aude YW, et al. Arch Intern Med. 2004 Oct 25;164(19):2141-6.
  17. Brehm BJ, et al. J Clin Endocrinol Metab. 2003 Apr;88(4):1617-23.
  18. Sondike SB, et al. J Pediatr. 2003 Mar;142(3):253-8.
  19. Samaha FF, et al. N Engl J Med. 2003 May 22;348(21):2074-81.
  20. Foster GD, et al. N Engl J Med. 2003 May 22;348(21):2082-90.
  21. Guldbrand, et al. Diabetologia. 2012 Aug;55(8):2118-27.
  22. Westman EC, et al. Nutr Metab (Lond). 2008 Dec 19;5:36.
  23. Daly ME, et al. Diabet Med. 2006 Jan;23(1):15-20.

Main Results:

Low-carb diets usually lead to more weight loss than low-fat diets, even when the low-fat groups are calorie restricted while the low-carb groups are not.

Low-carbohydrate diets also significantly improve major risk factors for diseases like cardiovascular disease and type II diabetes.

Meta-Analyses of Low-Carb Diet Studies

These studies are meta-analyses of randomized controlled trials of low-carbohydrate diets.

  1. Santos F, et al. Obesity Reviews, 13: 1048–1066.
  2. Hession M, et al. Obesity Reviews, 10: 36–50.
  3. Westman EC, et al. Am J Clin Nutr August 2007 86: 2 276-284

Main Results:

Same as above. Low-carb diets lead to more weight loss and further improvements in metabolic health compared to low-fat diets.

The Paleolithic Diet

Randomized controlled trials of the paleolithic diet (commonly known as the paleo diet or caveman diet).

  1. Jönsson T, et al. Cardiovascular Diabetology 2009, 8:35.
  2. Lindeberg S, et al. Diabetologia. 2007 Sep;50(9):1795-807.

Main Results:

The paleo diet has favorable effects on body weight and major risk factors. However, the studies available are very small so the results must be taken with a grain of salt.

Vitamin D3 Supplementation

A deficiency in vitamin D is very common today, especially in countries where there is little sun throughout most of the year.

  1. Lappe JM, et al. Am J Clin Nutr. 2007 Jun;85(6):1586-91.
  2. Meta-analysis: Bischoff-Ferrari HA, et al. JAMA. 2005 May 11;293(18):2257-64.
  3. Trivedi DP, et al. BMJ 2003;326:469.
  4. Broe KE, et al. J Am Geriatr Soc. 2007 Feb;55(2):234-9.
  5. Urashima M, et al. Am J Clin Nutr May 2010.

Main Results:

Vitamin D supplementation reduces risk of falls and fractures in the elderly at higher doses. Vitamin D may reduce risk of cancer and respiratory infections.

Anything Else?

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There is no cherry picking here. All relevant studies are included.

An evidence-based nutrition article from our experts at Authority Nutrition.

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