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By: Annabelle Shaffer, Dietetics senior at University of Illinois Urbana-Champaign

Overview of Ketogenic Diets

The ketogenic diet, popularly known as the keto diet, is low in carbohydrates, moderate in protein, and high in fat.1 While an official definition is not recognized, carbohydrates are often restricted to less than 50 g per day.1 A balanced diet typically consists of 45-65% daily calories from carbohydrates (or 225-325 g when following a 2000 calorie/day diet), 10-35% from protein, and 20-35% from fats.

The diet was initially used in the 1920s for epilepsy therapy.1 Now, the ketogenic diet is promoted by Instagram influencers, medical doctors, and bloggers as a successful weight loss, dyslipidemia, and metabolic syndrome treatment.

With obesity rates on the rise, it is important to explore different avenues of weight loss methods. In this post, we will delve into the science surrounding the ketogenic diet for weight loss.

What does the science say? 

Low-fat diets are commonly recommended for weight loss, but recent randomized controlled trials have compared the ketogenic and low-fat diet’s effectiveness in weight loss. Thus far, studies have shown that low carbohydrate diets induce greater short-term weight loss than a balanced diet, but the diets are equally successful long-term:

  • “In this meta-analysis of randomized controlled trials comparing the effects of low-carbohydrate vs low-fat diets, low-carbohydrate diets were more effective in inducing weight loss after 6 months, but this effect was no longer obvious after 12 months of follow-up”2
  • “Our results show that the weight loss in overweight and obese subjects with or without diabetes on isoenergetic low CHO or balanced weight loss diets was similar at 3–6 months and at 1–2 years”3

We do not yet know the effectiveness of a ketogenic diet, nor have we identified the mechanism behind the weight loss it can cause. Traditional weight-loss diets work on the principle of consuming fewer calories than a person burns during everyday living and exercise. Possibilities for weight loss on the keto diet include:

  • Increased satiety due to protein consumption1
  • Reduction in lipogenesis (the synthesis of fat in the body) and increased lipolysis (the breakdown of fat in the body)1
  • Increased metabolic efficiency due to higher fat consumption1
  • Increased energy expended in gluconeogenesis (the synthesis of glucose, a type of sugar, in the body)1

It is important to be mindful that ketogenic diets are difficult to stay on for long and many nutrient-dense foods are rich in carbohydrates, such as fruits, vegetables, dairy products, whole grains (oats, rice, wheat), and legumes. Also, the long-term health impacts of a ketogenic diet remain unknown as many studies have a 6-month to a year duration. Finally, a high-fat diet can have negative health impacts including increased total cholesterol and LDL-cholesterol.2 Due to insufficient supporting evidence for the ketogenic diet, a balanced diet and exercise plan is still the recommended route towards weight loss for the general population.4

To learn more about the Ketogenic diet please watch our free, on-demand webinar The Ketogenic Diet-Is it Another Fad? 



  1. Paoli A, Rubini A, Volek J, Grimaldi K. Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. Eur J Clin Nutr. 2013;67(8):789-796. doi:10.1038/ejcn.2013.116
  2. Nordmann A, Nordmann A, Briel M et al. Effects of Low-Carbohydrate vs Low-Fat Diets on Weight Loss and Cardiovascular Risk Factors. Arch Intern Med. 2006;166(3):285. doi:10.1001/archinte.166.3.285
  3. Naude C, Schoonees A, Senekal M, Young T, Garner P, Volmink J. Low Carbohydrate versus Isoenergetic Balanced Diets for Reducing Weight and Cardiovascular Risk: A Systematic Review and Meta-Analysis. PLoS ONE. 2014;9(7):e100652. doi:10.1371/journal.pone.0100652
  4. Jensen M, Ryan D, Donato K et al. Executive summary: Guidelines (2013) for the management of overweight and obesity in adults. Obesity. 2014;22(S2):S5-S39. doi:10.1002/oby.20821

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