Why you may not be losing weight on the keto diet

Most people who do the keto diet will lose weight, but you have to follow it strictly and be in a calorie deficit to make it work. 

Over time, you may hit a "keto plateau" where you will stop losing weight, even while following the same diet.

Even if you don't lose weight, a slightly higher number on the scale may not always be a bad sign if you are gaining muscle.

This article was reviewed by Samantha Cassetty, MS, RD, nutrition and wellness expert with a private practice based in New York City.

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The keto diet has exploded in popularity as a way to lose weight and improve health. But not everyone loses weight on keto, and some stop losing weight after a few months. If you aren't meeting your weight goals, you may need to make some adjustments or talk with a registered dietitian.

First, make sure you are in ketosis

The main purpose of the keto diet is to send your body into ketosis. In ketosis, your metabolism shifts and starts to burn fat instead of carbohydrates to fuel your body. 

However, it can take a lot of careful planning to put your body into ketosis. While on keto, your diet is made up of 60% to 75% fat, 20% to 30% protein, and 5% to 10% carbohydrates. This goes against the usual American diet, which is over 50% carbohydrates. 

You can check to see if you are really in ketosis using at-home urine test strips. These strips detect ketones, substances your liver creates when processing fat. However, being in ketosis is not going to make you lose weight if you are still taking in too many calories, says Scott Keatley, RD, a dietitian at Keatley Medical Nutrition Therapy.

Most people lose weight on keto if they do it correctly

If people are following the keto diet correctly, it's pretty rare to not lose any weight, says Keatley.

But losing weight on the keto diet is like losing weight on any diet — you need to burn more calories in the day than you consume. The restriction does not need to be extreme, but you should be at a caloric deficit. Ketosis makes this a little easier since it reduces your appetite so you're less hungry and therefore, less likely to overeat.

However, if you restrict calories too much — to less than 1,200 per day for the average adult — this can also slow your weight loss goals. Because when you don't eat enough it can send your body into starvation mode, where your metabolism slows down and you may stop losing weight.

Side note: If you are using the keto diet for health reasons and not aiming to lose weight, putting your body into ketosis may help — provided you're following the diet in a healthy manner by, for example, minimizing processed and red meats and prioritizing plant-based fats, like avocados, olives, and nuts. 

The keto plateau

Even if you are keeping your metabolism up, your weight loss may still slow down over time. As you cut calories and lose weight, your body will adapt to the change and start needing fewer calories to keep itself going, says Keatley. In other words, people tend to hit a weight loss plateau. 

However, Keatley says that you should not use the scale as your only measure of progress. Lean muscle is denser than fat, so burning fat and building muscle can actually lead to a slight weight increase. "The scale may freak you out when the change happening is positive," Keatley says.

Finally, the keto diet can have some extreme restrictions on food. If you're considering trying the keto diet to lose weight, Keatley says, "I would advise anyone thinking of a keto diet to talk to their doctor and a dietitian before, during and after."