While the ketogenic dietary lifestyle is surging in popularity, it’s not new. In fact, doctors were prescribing low-carbohydrate diets to patients as far back as the late 1800’s as a way to improve health & reduce bodyfat. As I’ve traveled on my low-carb/high fat (LCHF) journey, evolving into practicing the ketogenic dietary lifestyle (KDL), one of the most puzzling aspects for me is how much scientific research has been done to demonstrate the power of LCHF, that has not been shared with the broader population. I aim to change that with this reference page on http://www.business-fit.org, in the hopes that people who are interested-in, curious about, or have preconceived notions regarding LCHF and KDL, will be able to use this site as a reference and data-based resource guide to see the research that proves the power of these lifestyles for themselves.
LCHF vs. KDL: What’s the Difference?
You will, even in the below research papers, see medical and research professionals use LCHF and KDL interchangeably, which is simply inaccurate. They are not the same, and as a foundation, it’s important to understand the differences.
On the LCHF diet, the general guidance is to consume no more than 130 – 150 grams of carbohydrates per day, which using a 2,000 calorie/day diet, means approximately 25% – 30% of calories from carbohydrates. The remaining 70% of calories will be consumed from fats & proteins in a ratio of 50% – 60% fat / 10% – 20% protein. On this diet, the body still has ample carbohydrates to operate with glycogen (glucose stored in the muscle) as the primary fuel source, except in instances where glycogen is being aggressively depleted, such as with high performance athletes.
On the KDL, the general guidance is to consume no more than 40 grams of carbohydrates per day, which using a 2,000 calorie/day diet, means 5% – 10% of calories from carbohydrates. The remaining 90% of calories will be consumed from fats & proteins in a ratio of 65% – 80% fat / 10% – 25% protein. Some KDL practitioners may increase their protein consumption up to 30% of calories, but that would be the ceiling. On this diet, the body shifts from burning primarily glycogen to ketones (fats) as fuel. Basically, fat becomes the primary source of fuel, and as the body needs a small bit of glycogen, it is very-well equipped to convert other molecules (ie, lactase, proteins, fats) to energy through processes like lipolysis and gluconeogenisis.
A good starting point in seeking out references on whether the LCHF dietary lifestyle is safe and effective is to review the below published article. In addition to providing a synopsis of research that answers questions about safety, weight loss, type 2 diabetes impact & the contribution (or lack there-of) to cardiovascular disease, there are well over 100 references and acknowledgements that can take you into more detail at you leisure. There is likely a lot more research around this lifestyle than you may have thought, and the results around the health benefits are surprisingly consistent and powerful.
Research, Studies, Meta-analyses & Trials: Understanding the Science
The below reference list is divided into sections of interest in an effort to show just a sample of the depth of scientific rigor that has been applied to LCHF and KDL lifestyles. The sections are as follows:
- Weight Loss
- Type 2 Diabetes (T2D)
- Metabolic Disease / Metabolic Syndrome
- Fats & Inflammation
- Digestive & Gastrointestinal Relief
- Coronary Artery Disease
(2004). A randomized trial. The national cholesterol education program diet vs a diet lower in carbohydrates and higher in protein and monounsaturated fat. https://pubmed.ncbi.nlm.nih.gov/15505128/
(2007). A randomized trial. 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. https://jamanetwork.com/journals/jama/fullarticle/205916
(2018). A randomized trial. Effects of a low carbohydrate diet on energy expenditure during weight loss maintenance. https://www.bmj.com/content/363/bmj.k4583
(2021). Study participants from the Raine Study. Prospective Associations of Sugar-Sweetened Beverage Consumption During Adolescence with Body Composition & Bone Mass at Early Adulthood. https://academic.oup.com/jn/article/152/2/399/6430171
(2022). Article describing the risks/issues with Sucralose as an artificial sweetener. https://usrtk.org/sweeteners/sucralose-emerging-science-reveals-health-risks/
Type 2 Diabetes (TD2)
(2005). Small Control Study. Ketogenic diet to treat T2D. https://pubmed.ncbi.nlm.nih.gov/16318637/
(2013). Meta-analysis. Dietary approaches to managing T2D. https://pubmed.ncbi.nlm.nih.gov/23364002/
(2017). Randomized Trial. Twelve-month outcome diet comparison of adults with T2D. https://www.nature.com/articles/s41387-017-0006-9#Sec7
(2017). Data Review. Autophagy and its link to T2D. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5479440/
(2019). Virta Health 2-year Study. Evidence to support a ketogenic diet to reverse T2D. https://www.virtahealth.com/blog/2yr-t2d-trial-outcomes-virta-nutritional-ketosis
(2020). Small Control Study. Effect of Artificial Sweeteners on Insulin Resistance among T2D. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7014832/#ref7
Metabolic Disease / Metabolic Syndrome
(2003). Data review. Clinical use of a carbohydrate-restricted diet & metabolic syndrome. https://pubmed.ncbi.nlm.nih.gov/18370666/
(2008). Randomized Control Trial. Long-term effects of a very low carbohydrate diet. https://pubmed.ncbi.nlm.nih.gov/19439458/
(2008): Small Control Study. Dietary Cholesterol from Eggs Increases Plasma HDL in men consuming a Carbohydrate Restricted Diet. https://academic.oup.com/jn/article/138/2/272/4664988
(2009). Randomized Control Trial. Carbohydrate restriction vs. low fat on metabolic syndrome. https://pubmed.ncbi.nlm.nih.gov/19082851/
(2012). Meta-analysis. Low-carbohydrate diet and cardiovascular risk factors. https://pubmed.ncbi.nlm.nih.gov/22905670/
(2021). Article from the American Journal of Clinical Nutrition. The Carbohydrate-Insulin Model & the Obesity Pandemic. https://academic.oup.com/ajcn/advance-article/doi/10.1093/ajcn/nqab270/6369073
Fats & Inflammation
(2005). Editorial. Obesity & Visceral fat: a growing inflammatory disease. https://www.nature.com/articles/ncpgasthep0197
(2014). Randomized Control Trial. Advice to follow a low-carbohydrate diet has a favorable impact on low-grade inflammation. https://pubmed.ncbi.nlm.nih.gov/24779961/
(2014). Meta-analysis. Association of Dietary, Circulating, and Supplement Fatty Acids with Coronary Risk. https://pubmed.ncbi.nlm.nih.gov/24723079/
(2020). Blog post written by Healthline Nutrition Team Member, Adda Bjarnadottir. Five studies done to demonstrate no link between saturated fat and heart disease. https://www.healthline.com/nutrition/5-studies-on-saturated-fat
(2018). Meta-analysis. How Much Protein Can the Body Use in a Single Meal for Muscle Building? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5828430/
Digestive and Gastrointestinal Relief
(2016). Prospective Study. Clinical and Fecal Microbial Changes With Diet Therapy in Active Inflammatory Bowel Disease. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5484760/
Coronary Artery Disease (CAD)
(2009). Analysis. Lipid Levels in Patients Hospitalized with Coronary Artery Disease. https://pubmed.ncbi.nlm.nih.gov/19081406/
(2010). Meta-analysis. Red and Processed Meat Consumption and Risk of Coronary Heart Disease. https://pubmed.ncbi.nlm.nih.gov/20479151/
(2010). Meta-analysis. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. https://pubmed.ncbi.nlm.nih.gov/20071648/
(2010). Article & Analysis. Atherogenic Dyslipidemia: Cardiovascular Risk and Dietary Intervention. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2950930/
(2017). Article & Analysis. β-Hydroxybutyrate Deactivates Neutrophil NLRP3 Inflammasome to Relieve Gout Flares. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5527297/