Why am I not losing weight on the keto diet?

Get to the bottom of what might be putting the brakes on weight loss when you’re doing keto.
Published 16 September 2019 | Updated 25 June 2024

Setting yourself a weight loss goal, changing your eating habits in a way that you believe will help and then not actually losing any weight is the definition of frustrating, right? We get it. And it turns out there could be a number of reasons why you’re not losing weight on the keto diet.

1/ You’re eating too many carbs

Keto isn’t just a low-carbohydrate diet, it’s an extreme low-carbohydrate diet, so it’s not difficult to overdo it unless you audit your diet pretty closely. And if you are eating too many carbohydrates, it means you’re not giving your body a chance to flick over into the all-important ketosis, where your body uses ketones produced from stored fat for fuel, instead of glucose from carbohydrates.

Depending on your body’s individual needs, keto demands not eating any more than 20 to 50 grams of carbohydrate a day. And while some sources of carbohydrate are obvious, like pasta, potatoes and bread, others fly a little further under the radar. Don’t forget that legumes, starchy vegetables, most fruit and even yoghurt contain plenty of carbohydrate.

2/ You’re eating too many kilojoules

Weight loss only occurs if you consume fewer kilojoules than your body burns. And unlike other eating plans that don’t require counting kilojoules, the key to keto success is knowing how many kilojoules will encourage weight loss for you personally, and then doing some calculations and applying the keto ratio so you know how much fat, protein and carbohydrate you can eat.

3/ You’re not getting enough sleep

Studies continue to prove the link between both lack of sleep and inconsistent sleep patterns with less successful weight loss. One explanation is that sleep deprivation increases levels of a hormone that triggers hunger. Unfortunately, difficulty either falling or staying asleep can be a side effect of keto for a few weeks after you first start, perhaps due the way severely restricting carbohydrates affects brain chemicals that influence sleep.

Gaining weight on keto

Like we mentioned above, regardless of the eating plan you’re following, you’ll only lose weight if you consume less energy than your body burns, and some eating plans make it easier to get that balance right than others.

While keto does prescribe the ratio of fat, protein and carbohydrates you need to aim for, to make that work you have to know the total amount of kilojoules you want to stick to, and apply the ratio to that number. Without doing your sums carefully, eating too many kilojoules is a real possibility. And particularly when keto puts you in the mindset of needing to eat a large amount of fat, which is the most concentrated source of energy, containing twice as many kilojoules per gram than carbohydrates or protein.

Why am I bloated on keto?

A common cause of bloating is constipation, something that can be a side effect of keto in the days and weeks after starting. On top of the fact that restricting carbohydrates reduces fibre intake, it also makes dehydration more likely, and both are risk factors for constipation. While valuable sources of fibre, like legumes, wholegrain breads and cereals and fruit have to remain off limits, people following keto should strive to eat the maximum amount of ‘keto approved vegetables’, like leafy green vegetables, and make a conscious effort to drink plenty of water.

Keto weight fluctuations

The majority of any weight loss that might initially occur on keto is ‘water weight’. With dietary carbohydrates and therefore glucose restricted, the body pulls and uses stored glucose from the liver, a process which also causes water levels in the body, and therefore the number on the scales, to fall. When you start eating carbohydrates again, the process is reversed and this ‘weight’ will return. So, stopping and starting keto simply by eating too many carbohydrates on the odd day, could explain weight fluctuations.

Weight gain after stopping keto

The majority of people following very restrictive weight loss diets regain the weight, and often more, back once they stop following the diet and resume their usual pre-diet eating patterns and behaviours.

But the ‘water weight’ scenario outlined above may also be an explanation. People who only follow the diet for a little while before returning to usual eating habits, will experience ‘water weight regain’ after stopping keto.