Here are a few of the most common side effects that I come across when people first start keto. Frequently the issues relate to dehydration or lack of micronutrients (vitamins) in the body. Make sure that you’re drinking enough water (close to a gallon a day) and eating foods with good sources of micronutrients. To read more on micronutrients, click here >
Katherine Arvesen, RDN, who in private practice in Plano, Texas, also notes that the study was not randomized and controlled, which is the gold standard for medical research to minimize error and bias. In this study, the patients were their own controls, meaning their results were compared with their own baseline (starting) measurements, not with the results of a control group.
To drill down further, there are some genetic enzyme defects that cause problems with ketosis. Here are a few of note: carnitine deficiency (primary), carnitine palmitoyltransferase (CPT) I or II deficiency, carnitine translocase deficiency, beta-oxidation defects—mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (mHMGS) deficiency, medium-chain acyl dehydrogenase deficiency (MCAD).
Table 2 contains the correlation matrix that assessed the association between the changes in the physical and psychological states. Many relevant R-coefficients were found, confirming that changes in body composition (BMI, FM, FFM, and weight) and ketosis were strongly related to the differences in food craving, alcohol craving, sleep patterns, physical activity, and sexual activity. These associations emerged when changes between baseline and maximum ketosis were assessed, and they remained quite similar for changes estimated between baseline and reduced ketosis or endpoint. Regarding the ketosis change levels, associations emerged with some subscales in all the psychological questionnaires, except for the FCI scales and the multidimensional alcohol craving measures.
If you’ve decided to move forward in trying the keto diet, you will want to stick to the parameters of the eating plan. Roughly 60 to 80 percent of your calories will come from fats. That means you’ll eat meats, fats, and oils, and a very limited amount of nonstarchy vegetables, she says. (This is different from a traditional low-carb diet, as even fewer carbs are allowed on the keto diet.)
If you need to eat more or fewer calories per day, you can adjust accordingly by simply taking out or adding a bit more of the ingredients already included in a recipe. For example, adding/removing a tablespoon of olive oil or butter will add/remove about 100 calories. If you like or dislike certain recipes, feel free to shift things around. Make sure to keep an eye on the calories so you’re still falling within an acceptable range of your daily goal.
This is because the triglycerides from those fat cells are metabolized for energy while the cholesterol is not. The cholesterol is simply released into the blood where it will remain until removed by the liver, making it appear that our cholesterol has suddenly skyrocketed. Many people are quick to assume that this is due to an increase in dietary fat and cholesterol intake.

In the first week, many people report headaches, mental fogginess, dizziness, and aggravation. Most of the time, this is the result of your electrolytes being flushed out, as ketosis has a diuretic effect. Make sure you drink plenty of water and keep your sodium intake up.6One of the fathers of keto, Dr. Phinney, shows that electrolyte levels (especially sodium) can become unbalanced with low carb intake.