The nutrition and fitness industry is constantly trying to sell you the secret, but when you control for calories, protein, and fiber no diet is likely to result in more fat loss than another [1-3].

Paleo, Keto, Zone, Carnivore, Vegan, Lacto-Ovo-Fruitarian, I don’t care…if you control for the variables above it very VERY likely isn’t going to matter for fat loss.

The messaging of the Keto world over the past decade has duped us into thinking that we can’t lose body fat while eating carbohydrates. 

This is laughably false…wrong…not true....a lie [2, 4-52].

Just the fact that so many people have gotten results going plant based should cue us in that when we control for calories massive differences in dietary philosophies can BOTH result in significant fat loss.

Just to prove a point, people have lost massive amounts of body fat eating ONLY ice cream, Twinkies, potatoes, or white rice [29, 53].

Here is the dirty little secret that those selling Keto, Vegan, or Paleo diets don’t want you to know…the number one secret for short and long-term success doesn’t come from restricting entire food groups it comes from Dietary Adherence [54].

And if you look at the long-term studies on these types of extreme and restrictive dietary approaches most of us regular people can’t seem to maintain them [6, 8, 55].

In fact, by the end of these interventions, the researchers don’t even know what to call the diets because the people aren’t able to stick to the philosophy at six months and one year [6, 8].

Keto turns into a moderate carbohydrate approach and the fat content inevitably creeps up in the plant-based group.

It doesn’t look like most people can sustain carbohydrate intakes lower than 140 grams long-term [56] and there are five times more former vegan and vegetarians than current vegan and vegetarians which kind of highlights that this philosophy may not be super sustainable [57]. These all-or-nothing rigid dietary schematics also very likely have psychological downsides and can be prone to the “what-the-hell” effect where people go off the diet and repeatedly crash into a pool of chips and queso [58-62].

So why would we start with something that is likely unsustainable and isn’t going to get us any better results?

I can think of exactly zero reasons...other than we may feel peer-pressured into these types of rigid diets because our friends and family may have seen results with them. But, they very likely didn't need to go with such restrictive approaches to get their results, and unfortunately the research tells us that they are unlikely to be able to stick to these types of diets in their original form long-term. 

I know this entire topic is confusing and as a scientist I genuinely wish in my heart of hearts that weight regulation was just as simple as restricting carbohydrates or fat, but it’s not and it never will be.

We will always want simple stories and many people read the paragraphs above and think we will never have the answer, but we already do!

A multitude of different dietary schematics can absolutely be healthy and result in significant body composition changes.

I can’t think of a more freeing sentence.

The secret key isn’t out there hidden on the internet somewhere.

The secret is working to find the dietary approach that works for YOU long-term.

#GIVEAFIT

REFERENCES:

1. Veum, V.L., et al., Visceral adiposity and metabolic syndrome after very high-fat and low-fat isocaloric diets: a randomized controlled trial. Am J Clin Nutr, 2017. 105(1): p. 85-99.

2. Vidic, V., et al., Effects of calorie restricted low carbohydrate high fat ketogenic vs. non-ketogenic diet on strength, body-composition, hormonal and lipid profile in trained middle-aged men. Clin Nutr, 2021. 40(4): p. 1495-1502.

3. Aragon, A.A., et al., International society of sports nutrition position stand: diets and body composition. J Int Soc Sports Nutr, 2017. 14: p. 16.

4. Tay, J., et al., Comparison of low- and high-carbohydrate diets for type 2 diabetes management: a randomized trial. Am J Clin Nutr, 2015. 102(4): p. 780-90.

5. Tay, J., et al., Effects of an energy-restricted low-carbohydrate, high unsaturated fat/low saturated fat diet versus a high-carbohydrate, low-fat diet in type 2 diabetes: A 2-year randomized clinical trial. Diabetes Obes Metab, 2018. 20(4): p. 858-871.

6. Gardner, C.D., et al., Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial. JAMA, 2007. 297(9): p. 969-77.

7. Gardner, C.D., et al., Weight loss on low-fat vs. low-carbohydrate diets by insulin resistance status among overweight adults and adults with obesity: A randomized pilot trial. Obesity (Silver Spring), 2016. 24(1): p. 79-86.

8. Gardner, C.D., et al., Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion: The DIETFITS Randomized Clinical Trial. JAMA, 2018. 319(7): p. 667-679.

9. Hall, K.D., A review of the carbohydrate-insulin model of obesity. Eur J Clin Nutr, 2017.

10. Hall, K.D. and J. Guo, Obesity Energetics: Body Weight Regulation and the Effects of Diet Composition. Gastroenterology, 2017. 152(7): p. 1718-1727 e3.

11. Hulmi, J.J., et al., The Effects of Intensive Weight Reduction on Body Composition and Serum Hormones in Female Fitness Competitors. Front Physiol, 2016. 7: p. 689.

12. Mitchell, L., et al., Physiological implications of preparing for a natural male bodybuilding competition. Eur J Sport Sci, 2018: p. 1-11.

13. Peos, J.J., et al., Continuous versus Intermittent Dieting for Fat Loss and Fat-free Mass Retention in Resistance-trained Adults: The ICECAP Trial. Med Sci Sports Exerc, 2021.

14. Hall, K.D., et al., Effect of a plant-based, low-fat diet versus an animal-based, ketogenic diet on ad libitum energy intake. Nat Med, 2021. 27(2): p. 344-353.

15. Hall, K.D., et al., Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metab, 2019. 30(1): p. 226.

16. Campbell, D.D. and K.A. Meckling, Effect of the protein:carbohydrate ratio in hypoenergetic diets on metabolic syndrome risk factors in exercising overweight and obese women. Br J Nutr, 2012. 108(9): p. 1658-71.

17. Campbell, K.L., et al., Reduced-calorie dietary weight loss, exercise, and sex hormones in postmenopausal women: randomized controlled trial. J Clin Oncol, 2012. 30(19): p. 2314-26.

18. Campbell, W.W., et al., Resistance training preserves fat-free mass without impacting changes in protein metabolism after weight loss in older women. Obesity (Silver Spring), 2009. 17(7): p. 1332-9.

19. Conlin, L.A., et al., Flexible vs. rigid dieting in resistance-trained individuals seeking to optimize their physiques: A randomized controlled trial. J Int Soc Sports Nutr, 2021. 18(1): p. 52.

20. Jo, E., et al., Resistance training during a 12-week protein supplemented VLCD treatment enhances weight-loss outcomes in obese patients. Clin Nutr, 2019. 38(1): p. 372-382.

21. Fisher, G., et al., Effect of diet with and without exercise training on markers of inflammation and fat distribution in overweight women. Obesity (Silver Spring), 2011. 19(6): p. 1131-6.

22. Bryner, R.W., et al., Effects of resistance vs. aerobic training combined with an 800 calorie liquid diet on lean body mass and resting metabolic rate. J Am Coll Nutr, 1999. 18(2): p. 115-21.

23. Bouchard, D.R., et al., Impact of resistance training with or without caloric restriction on physical capacity in obese older women. Menopause, 2009. 16(1): p. 66-72.

24. Hernandez-Reyes, A., et al., Changes in body composition with a hypocaloric diet combined with sedentary, moderate and high-intense physical activity: a randomized controlled trial. BMC Womens Health, 2019. 19(1): p. 167.

25. Longland, T.M., et al., Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial. Am J Clin Nutr, 2016. 103(3): p. 738-46.

26. Gilardini, L., et al., Effect of a Modest Weight Loss in Normalizing Blood Pressure in Obese Subjects on Antihypertensive Drugs. Obes Facts, 2016. 9(4): p. 251-8.

27. Wycherley, T.P., et al., A high-protein diet with resistance exercise training improves weight loss and body composition in overweight and obese patients with type 2 diabetes. Diabetes Care, 2010. 33(5): p. 969-76.

28. van Gemert, W.A., et al., Effect of weight loss, with or without exercise, on body composition and sex hormones in postmenopausal women: the SHAPE-2 trial. Breast Cancer Res, 2015. 17: p. 120.

29. Kempner, W., et al., Treatment of massive obesity with rice/reduction diet program. An analysis of 106 patients with at least a 45-kg weight loss. Arch Intern Med, 1975. 135(12): p. 1575-84.

30. Flechtner-Mors, M., et al., Effects of moderate consumption of white wine on weight loss in overweight and obese subjects. Int J Obes Relat Metab Disord, 2004. 28(11): p. 1420-6.

31. Gaesser, G.A., J. Miller Jones, and S.S. Angadi, Perspective: Does Glycemic Index Matter for Weight Loss and Obesity Prevention? Examination of the Evidence on "Fast" Compared with "Slow" Carbs. Adv Nutr, 2021.

32. Galindo Munoz, J.S., et al., Effect of a chronotype-adjusted diet on weight loss effectiveness: A randomized clinical trial. Clin Nutr, 2020. 39(4): p. 1041-1048.

33. Seimon, R.V., et al., Effect of Weight Loss via Severe vs Moderate Energy Restriction on Lean Mass and Body Composition Among Postmenopausal Women With Obesity: The TEMPO Diet Randomized Clinical Trial. JAMA Netw Open, 2019. 2(10): p. e1913733.

34. Bray, G.A., et al., Markers of dietary protein intake are associated with successful weight loss in the POUNDS Lost trial. Clin Obes, 2017. 7(3): p. 166-175.

35. Vadiveloo, M., H. Parker, and H. Raynor, Increasing low-energy-dense foods and decreasing high-energy-dense foods differently influence weight loss trial outcomes. Int J Obes (Lond), 2018. 42(3): p. 479-486.

36. Ebbeling, C.B., et al., Effects of a low-glycemic load vs low-fat diet in obese young adults: a randomized trial. JAMA, 2007. 297(19): p. 2092-102.

37. Hall, K.D., et al., Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men. Am J Clin Nutr, 2016. 104(2): p. 324-33.

38. Sloth, B., et al., No difference in body weight decrease between a low-glycemic-index and a high-glycemic-index diet but reduced LDL cholesterol after 10-wk ad libitum intake of the low-glycemic-index diet. Am J Clin Nutr, 2004. 80(2): p. 337-47.

39. Johnston, C.S., et al., Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets. Am J Clin Nutr, 2006. 83(5): p. 1055-61.

40. Naude, C.E., et al., Low carbohydrate versus isoenergetic balanced diets for reducing weight and cardiovascular risk: a systematic review and meta-analysis. PLoS One, 2014. 9(7): p. e100652.

41. Pasiakos, S.M., et al., Effects of testosterone supplementation on body composition and lower-body muscle function during severe exercise- and diet-induced energy deficit: A proof-of-concept, single centre, randomised, double-blind, controlled trial. EBioMedicine, 2019. 46: p. 411-422.

42. Pasiakos, S.M., et al., Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial. FASEB J, 2013. 27(9): p. 3837-47.

43. Byrne, N.M., et al., Intermittent energy restriction improves weight loss efficiency in obese men: the MATADOR study. Int J Obes (Lond), 2018. 42(2): p. 129-138.

44. Verreijen, A.M., et al., Effect of a high protein diet and/or resistance exercise on the preservation of fat free mass during weight loss in overweight and obese older adults: a randomized controlled trial. Nutr J, 2017. 16(1): p. 10.

45. Campos-Nonato, I., L. Hernandez, and S. Barquera, Effect of a High-Protein Diet versus Standard-Protein Diet on Weight Loss and Biomarkers of Metabolic Syndrome: A Randomized Clinical Trial. Obes Facts, 2017. 10(3): p. 238-251.

46. Rock, C.L., et al., Randomized clinical trial of portion-controlled prepackaged foods to promote weight loss. Obesity (Silver Spring), 2016. 24(6): p. 1230-7.

47. Cook, C.M., et al., A Commercially Available Portion-Controlled Diet Program Is More Effective for Weight Loss than a Self-Directed Diet: Results from a Randomized Clinical Trial. Front Nutr, 2017. 4: p. 55.

48. Garthe, I., et al., Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exerc Metab, 2011. 21(2): p. 97-104.

49. Campbell, B.I., et al., Effects of High Versus Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes Engaging in an 8-Week Resistance Training Program. Int J Sport Nutr Exerc Metab, 2018. 28(6): p. 580-585.

50. Huang, R.Y., et al., Vegetarian Diets and Weight Reduction: a Meta-Analysis of Randomized Controlled Trials. J Gen Intern Med, 2016. 31(1): p. 109-16.

51. Nicklas, B.J., et al., Effect of exercise intensity on abdominal fat loss during calorie restriction in overweight and obese postmenopausal women: a randomized, controlled trial. Am J Clin Nutr, 2009. 89(4): p. 1043-52.

52. Turner-McGrievy, G.M., N.D. Barnard, and A.R. Scialli, A two-year randomized weight loss trial comparing a vegan diet to a more moderate low-fat diet. Obesity (Silver Spring), 2007. 15(9): p. 2276-81.

53. Collier, R., This spud's for you: a two-month, tuber-only diet. CMAJ, 2010. 182(17): p. E781-2.

54. Alhassan, S., et al., Dietary adherence and weight loss success among overweight women: results from the A TO Z weight loss study. Int J Obes (Lond), 2008. 32(6): p. 985-91.

55. Hession, M., et al., Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities. Obes Rev, 2009. 10(1): p. 36-50.

56. Huntriss, R., M. Campbell, and C. Bedwell, The interpretation and effect of a low-carbohydrate diet in the management of type 2 diabetes: a systematic review and meta-analysis of randomised controlled trials. Eur J Clin Nutr, 2017.

57. van Vliet, S., S.L. Kronberg, and F.D. Provenza, Plant-Based Meats, Human Health, and Climate Change. Frontiers in Sustainable Food Systems, 2020. 4(128).

58. Palascha, A., E. van Kleef, and H.C. van Trijp, How does thinking in Black and White terms relate to eating behavior and weight regain? J Health Psychol, 2015. 20(5): p. 638-48.

59. Smith, C.F., et al., Flexible vs. Rigid dieting strategies: relationship with adverse behavioral outcomes. Appetite, 1999. 32(3): p. 295-305.

60. Westenhoefer, J., et al., Cognitive and weight-related correlates of flexible and rigid restrained eating behaviour. Eat Behav, 2013. 14(1): p. 69-72.

61. Polivy, J., Psychological consequences of food restriction. J Am Diet Assoc, 1996. 96(6): p. 589-92; quiz 593-4.

62. Helms, E.R., K. Prnjak, and J. Linardon, Towards a Sustainable Nutrition Paradigm in Physique Sport: A Narrative Review. Sports (Basel), 2019. 7(7).