Following a ketogenic diet will not guarantee weight loss. Producing a lot of ketones does not mean you are shredding body fat. Gulping down shots of olive oil or putting butter in your coffee won’t make you thin.
You must consume fewer calories than you need, over time, to lose body fat.
This blog post will cover:
- What is Ketosis?
- Eating fat Makes You Burn More Fat for Energy but…
- Who is this Diet Good For?
- Who Should Avoid the Ketogenic Diet
What is Ketosis?
Ketosis is a metabolic state that occurs when the body does not have enough carbohydrate or total calories for energy. As a result, more fat is burned to fuel the body’s energy demands. As fat (dietary fat from the food you eat or body fat) is used, ketones are formed. When a person is in ketosis, ketones can be used as a source of energy (1). Being in ketosis or producing ketones is not the cause of weight loss. Instead it is the decrease in calories that leads to weight loss.
An in depth review of the ketogenic diet can be found here.
Eating Fat Makes You Burn More Fat for Energy but…
You use the macronutrients you eat for energy. Eat a high carbohydrate diet and you’ll use more carbohydrates for energy. Eat more fat and you’ll burn more fat (from your high fat diet) for energy. Using fat, from the coconut oil or butter you put your coffee, for energy is totally different than burning the fat on your body for energy. You must be in a caloric deficit for your body to use stored body fat for energy. Let’s say it’s 4 pm and you have eaten 1,000 calories so far today. But your daily needs, without exercise, are 2,300 calories per day. You are now using stored body fat for energy because you are in a calorie deficit (you haven’t eaten enough calories to cover your energy needs).
Can you lose weight on a ketogenic diet? Yes absolutely (2). However, from a purely scientific perspective, this is not the best diet for losing fat and maintaining or gaining muscle.
Research studies in humans show weight loss from a ketogenic diet is due to water, fat mass and muscle. Additionally, weight loss is likely due, in part, to limited food choices. After all, a stick of butter with drops of flavor and artificial sweeteners mixed in isn’t exactly something most people overeat at dessert time. No bread, rice, pasta, Oreos, Doritos, doughnuts, pizza… the list goes on and on. Another factor contributing to weight loss when on a ketogenic diet, at least for obese people, is a decrease in hunger over the short term. Research also shows on-going professional support is associated with greater weight loss when on a ketogenic diet (or any other diet) (3). Additionally, ramping up the protein in your diet and cutting calories alone (even if you aren’t following a ketogenic diet or you aren’t producing a ton of ketones) can improve body fat loss and help you maintain muscle.
Some studies report the ketogenic diet can have beneficial effects on cardiovascular disease risk factors while others show cholesterol and blood pressure increase. Why? It depends what you were eating and what you are eating now. If your diet consisted of fried foods, French fries and alcohol and you changed it to olive oil and salmon, I’m willing to bet your triglycerides, cholesterol and blood pressure will go down. If you were eating whole grains, legumes and salmon and started eating fatty red meat, butter and coconut oil, expect your cholesterol to shoot through the roof.
Aside from what you’re eating, weight loss has a huge effect on cardiovascular disease risk factors. If you are over fat and you lose a lot of weight, blood pressure, cholesterol and other cardiovascular disease risk factors will likely improve. Regardless of what you eat. A diet full of Twinkies can be beneficial for heart health risk factors as long as you lose weight.
Who is this Diet Good For?
The ketogenic diet effectively reduces the incidence and severity of seizures in epileptic patients resistant to medication. Ketogenic diets are being studied as potential therapeutic remedies for those with dementia and mental disorders. However, it s too soon to recommend these diets in patients with dementia or a mental disorder (4, 5).
As mentioned above, you can lose weight on this diet. If you love dietary fat, don’t like carbohydrate-rich foods and you are determined to try this diet, work with a MD and registered dietitian who are experts on ketogenic diets and have experience implementing these diets with their patients. There are many potential immediate and longer-term health consequences that may result following a ketogenic diet. These can be decreased or avoided when you follow the expert advice of a MD and RD.
Who Should Avoid the Ketogenic Diet?
This is not an easy diet to stick with. Anyone who is not going to take the time to plan it according to the directions of a RD (again, one who has worked with this diet; likely an outpatient RD who works with epileptic patients) should avoid trying a ketogenic diet. Also, anyone with a disease state or on medication should avoid it unless they talk to their MD first. Those with eating disorders or disordered eating, strength and power athletes as well as athletes engaged in high intensity sports should skip over ketogenic diets. There are better ways to lose fat and fuel your activity.
1 Wheless JW. History of the ketogenic diet. Epilepsia 2008;49 Suppl 8:3-5.
2 Bueno NB, de Melo IS, de Oliveira SL, da Rocha Ataide T. Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. Br J Nutr 2013;110(7):1178-87.
3 Kosinski C, Jornayvaz FR. Effects of Ketogenic Diets on Cardiovascular Risk Factors: Evidence from Animal and Human Studies. Nutrients 2017; 9(5): 517.
4 Bostock ECS, Kirkby KC, Taylor BVM. The Current Status of the Ketogenic Diet in Psychiatry. Front Psychiatry 2017; 8: 43.
5 Gasior M, Rogawski MA, Hartmana AL. Neuroprotective and disease-modifying effects of the ketogenic diet. Behav Pharmacol 2006; 17(5-6): 431–439.