There are many scenarios that can cause constipation with the ketogenic diet. Most people assume it’s a fiber issue; but it’s not that simple. You want to compare what you were doing before ketosis and after. Look at the change in vegetable fiber consumption; if you don’t have enough gut bacteria to digest all these vegetables, they will cause bloating, constipation, gas and all kinds of digestive issues. Some people can digest vegetables and others can’t. Some people can’t digest cabbage or cruciferous veggies. So, you might have to switch to less fibrous vegetables, such as various kinds of lettuce, and especially kale and beet greens, for your potassium. Electrolytes greatly help with constipation, too. If you need more support getting electrolytes, try my electrolyte powder. It helps supply the 4,700 mg a day of potassium you need, which is hard to manage without eating loads of vegetables. 
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than carbohydrates. Normally, the carbohydrates contained in food are converted into glucose, which is then transported around the body and is particularly important in fueling brain function. However, if there is little carbohydrate in the diet, the liver converts fat into fatty acids and ketone bodies. The ketone bodies pass into the brain and replace glucose as an energy source. An elevated level of ketone bodies in the blood, a state known as ketosis, leads to a reduction in the frequency of epileptic seizures.[1] Almost half of children and young people with epilepsy who have tried some form of this diet saw the number of seizures drop by at least half, and the effect persists even after discontinuing the diet.[2] There is some evidence that adults with epilepsy may benefit from the diet, and that a less strict regimen, such as a modified Atkins diet, is similarly effective.[1] The most common adverse effect is constipation, affecting about 30% of patients—this was due to fluid restriction, which was once a feature of the diet, but this led to increased risk of kidney stones and is no longer considered beneficial.[2][3]
A keto diet has shown to improve triglyceride levels and cholesterol levels most associated with arterial buildup. More specifically low-carb, high-fat diets show a dramatic increase in HDL and decrease in LDL particle concentration compared to low-fat diets.3A study in the long-term effects of a ketogenic diet shows a significant reduction in cholesterol levels, body weight, and blood glucose. Read more on keto and cholesterol >