Is the ketogenic diet (“keto”) a separate diet from a low-carb diet? Yes, it is different. It’s similar in many ways, but not one and the same, and the difference is apparent when it comes to weight loss.
So, without further ado, let’s dive right into it.
What is the difference between keto and low-carb?
Separating the two can get a little tricky.
“Low-carb” can refer to a few different diets – but the overarching similarity is – get this – the diets are low in carbohydrates. Of course, there are also diets (like Atkins) that fall somewhere in the middle.
The traditional low-carb diet is simply lower in carbohydrates than the average Western diet, and typically these carbs are usually replaced by higher protein intake. Fat can fall somewhere in the middle – it really depends on the preferences of the dieter.
Macros aren’t a huge deal, and most people don’t have a particular carb (or net carb) goal – if they do, they’re typically much higher than those found in keto.
Overall, a low-carb diet is a flexible definition, and often people following a low-carb diet are more flexible about their intake – perhaps just “cutting back” on things like bread and desserts in order to lose weight.
In comparison, keto is much stricter. Carbohydrate intake is minimized to the point where metabolic processes within the body are affected. Without going into great scientific detail, the body switches from using glucose (from carbohydrates) for energy to ketones (from fat).
When this happens, the body is in a state known as ketosis – which must be maintained indefinitely for keto benefits such as weight loss (or even the treatment of epilepsy, which was the original intent).
Keto diets are high in fat, have adequate protein and then are low in carbs. Usually, the macro-nutrient ratio is within the below ranges:
60-75% of calories from fat (or more)
15-30% of calories from protein, and
5-10% of calories from carbs
While the exact amount of fat and protein depends on an how your body responds and your activity level, most people don't consume over 5% of calories from carbohydrates while on a ketogenic diet.
The pie chart below shows the ratio of calorific contributions from food of the diets based on weight.
When following the ketogenic diet, carbohydrate intake typically needs to be below 50 grams per day – and some people will even drop this number as low as 20 to 25 grams per day, especially during the first few weeks.
The fat intake is usually very high in keto because it is being used for energy. Usually, protein macros are not as significant, and simply make up the remainder of the diet not occupied by fat and carbohydrates.
What is the difference between keto and low-carb for weight loss?
Here’s the thing – both keto and low-carb diets have been researched extensively for their benefits. Both can be used to successfully drop a substantial amount of weight fairly quickly and reap the health rewards of doing so – such as better blood glucose control in diabetes.
However, research specifically comparing the two diets in terms of weight loss is extremely limited, likely due to the overlap between the characteristics of both diets. Low-carb diets tend to allow for weight loss success much in the same way calorie-controlled diets do – simply by resulting in lower food intake.
Many people find that they have difficulty controlling themselves around high-carbohydrate foods – and by intentionally reducing the amount of these treats in their diet, they can better control their overall intake. Since low-carb diets tend to also be higher in protein, the extra protein can help to decrease appetite by improving satiety.
In contrast, keto relies on a person staying in ketosis to maintain existing weight loss and continue to lose weight. Just one high-carbohydrate “cheat meal” can be enough to knock the body out of ketosis and allow the weight to pile back on. As time goes on, carbohydrate limits can be loosened a bit, but they still need to remain low in order to maintain ketosis and keep the weight loss going.
Keto can be a difficult and tedious diet to stick with, but for the motivated person willing to try something new to lose weight, it can absolutely allow for long-term success.
In the end, both low-carb and ketogenic diets can provide substantial weight loss, but weight tends to come off more rapidly with keto, especially in the beginning. Low-carb diets allow a little more “wiggle room” in terms of veering slightly off the diet and maintaining success, while keto needs to be followed quite strictly for long-term success.
Additionally, low-carb diets tend to be easier to transition off once the weight has been lost in order to return to a “normal” diet. The transition off keto needs to be planned methodically and the diet tapered over a longer period to avoid the return of a substantial amount of weight.
Of course, both diets can be continued indefinitely if you wish to – so the sustainability of such a diet should certainly be taken into consideration before starting.