Unfortunately, there’s no long-term data on ketogenic diets versus other diets. In a 2015 Italian study, those on a ketosis diet lost 26 pounds in three months. About half of the participants stayed on the diet for a year but lost little additional weight in the next nine months. People in a 2014 Spanish study who followed a very-low-calorie ketogenic diet lost an average of 44 pounds in a year—but a third of them dropped out, possibly because it was too hard to maintain.
You can have a completely smooth transition into ketosis, or…not. While your body is adapting to using ketones as your new fuel source, you may experience a range of uncomfortable short-term symptoms. These symptoms are referred to as “the keto flu.” Low-sodium levels are often to blame for symptoms keto flu, since the kidneys secrete more sodium when you’re in ketosis, says Volek. A few side effects:
As your body breaks through the carb cycle and enters ketosis (where you rely on ketones, instead of carbs, for energy), you may experience fatigue, mental fogginess, even irritability. My "keto flu" only lasted a day, and once I passed it, I never experienced the symptoms again. I even ate a cookie one day during the diet to celebrate my birthday. I certainly came out of ketosis when I ate that treat, but I didn't experience any repercussions for it. 

The popular belief that high-fat diets cause obesity and several other diseases such as coronary heart disease, diabetes, and cancer has not been observed in recent epidemiological studies. Studies carried out in animals that were fed high-fat diets did not show a specific causal relationship between dietary fat and obesity. On the contrary, very-low-carbohydrate and high-fat diets such as the ketogenic diet have shown to beneficial to weight loss.
This work was supported by the PronoKal Group® and by grants from the Fondo de Investigacion Sanitaria (PE13/00024 and PI14/01012 research projects) and CIBERobn (CB06/003), Instituto de Salud Carlos III–Subdireccion General de Evaluacion y Fomento de la Investigación; Fondo Europeo de Desarrollo Regional, and the Health Department of the Xunta de Galicia, Spain. D.G.A. is grateful to the Colombian Department of Science, Technology and Innovation – COLCIENCIAS as a recipient of their predoctoral scholarship to support his work. The funding sources had no involvement in the study design, recruitment of patients, study interventions, data collection, or interpretation of the results. A PronoKal representative (I.S.) was involved in the study design and revised the final version of the manuscript, without intervention in the analysis of data, statistical evaluation, or final interpretation of the results of this study.
Klein S, Sheard NF, Pi-Sunyer S, Daly A, Wylie-Rosett J, Kulkarni K, Clark NG. Weight management through lifestyle modification for the prevention and management of type 2 diabetes: rationale and strategies. A statement of the American Diabetes Association, the North American Association for the Study of Obesity, and the American Society for Clinical Nutrition. Am J Clin Nutr. 2004;80:257–263. [PubMed] [Google Scholar]

I think you may be experiencing what I did on an ultra low carb diet. I did try to follow the "20 grams of carbs" approach but it didn't work for me. I felt sluggish, I was tired, and anxious (especially that anxiety!). Having said that, I have Hashimoto's (autoimmune hypothyroid condition) and I can't do very low-carb for that very reason. These days I eat 20-30 grams of net carbs, sometimes up to 50, especially after a workout when my body naturally craves carbs. Keep in mind that some people tend to overemphasise the importance of high ketones while it's not as simple and most people don't even need high ketones: The Ketone Craze - Who Really Benefits From High Ketone Levels? I hope this helps!
Ketones are a very effective fuel for the brain—often a more efficient fuel than glucose. Your body is like a hybrid car when it comes to fuel. When you run out of carbohydrates to burn for fuel—say you’re fasting before a surgery or a religious holiday—your body seeks an alternative way to get more fuel. (If your body didn’t do this, you would die after a short fast.) So the body kicks into burning fat, which is the metabolic state of ketosis, or “keto.” Technically, your liver takes long-chain and medium-chain fatty acids from your fat tissue, and produces a major ketone called beta-hydroxybutyrate (BHB). BHB provides more energy per unit oxygen used than glucose, which benefits the brain.

How it’s done: Warm up the LEVL or Ketonix meter by plugging it in. Blow into it and wait for the flashing light indicating it’s reading your acetone levels. The software or the color and speed of the flashing light would tell your reading: green for least acetone, red for most acetone, less flashing for less acetone per color, more flashing for more acetone per color.
Many people choose ketoproof coffee or tea in the morning to ramp up energy with added fats. While it is a great thing, it’s also important to consume flavored beverages in moderation. This is amplified when it comes to caffeine as too much will lead to weight loss stalls; try to limit yourself to a maximum of 2 cups of caffeinated beverages a day.
Dr. Vincent M. Pedre, medical director of Pedre Integrative Health and president of Dr. Pedre Wellness, is a board-certified internist in private practice in New York City since 2004. His philosophy and practices are a blend of both Western and Eastern medical traditions. He is a clinical instructor in medicine at the Mount Sinai School of Medicine and is certified in yoga and medical acupuncture. His unique methodology is best described as integrative or defined by a functional, systems-based approach to health. With his holistic understanding of both sides of the equation, he can help each patient choose the best course of action for their ailments to provide both immediate and long-term relief. His holistic approach incorporates positive, preventive health and wellness lifestyle choices. Dr. Pedre Wellness is a growing wellness platform offering health-enhancing programs along with informative social media and lifestyle products, such as dietary supplements, books, and weight-loss programs.

A Ketogenic diet is one that is high in healthy fats and proteins, and extremely low in carbohydrates.  Typically, it takes around 100g of carbohydrates per day to keep up with the average person's brain and organ function.  When you eat between 20-50 g of net carbohydrates (total carbohydrates – fiber) your body has to switch over to using fat to fuel itself instead of carbohydrates.  This process is called Ketosis, and it's a perfectly natural state of humans to exist in.
“I discovered the low-carb, ketogenic diet some four years ago and saw huge improvements in my own health. After establishing that it is based on sound scientific principles I felt compelled to offer it to my patients. We recommend the Diet Doctor website as it offers an unbiased, contemporary source of reliable low-carb ketogenic advice. It is easy to use and you can rely on its integrity.”

61. Thomson C.A., Morrow K.L., Flatt S.W., Wertheim B.C., Perfect M.M., Ravia J.J., Sherwood N.E., Karanja N., Rock C.L. Relationship between sleep quality and quantity and weight loss in women participating in a weight-loss intervention trial. Obesity. 2012;20:1419–1425. doi: 10.1038/oby.2012.62. [PMC free article] [PubMed] [CrossRef] [Google Scholar]

As you will see, simple keto meals begins with the healthy fat consideration first, making sure plenty of low-starch veggies surround the fat along with a moderate protein source. Wild-caught salmon, as a high-fat fish, is a perfect keto choice, and easy keto meals can be a fatty cut of healthy protein like salmon or lamb served with plenty of green veggies.
Excess fat mass (FM), especially visceral fat, is associated with a variety of pathological conditions such as hypertension, dyslipidemia, diabetes, and even cancer (1–4), as well as an increase in overall and cardiovascular mortality (2, 5). Very-low-calorie diets are commonly used as obesity treatments; however, a primary concern in using such diets is the amount of fat-free mass (FFM; i.e., muscular tissue) that is lost together with the FM (6). This could produce so-called sarcopenic obesity, that is, the coexistence of an excess of FM and a decline in FFM that yields a near-normal body weight (7). Sarcopenic obesity constitutes a double impact on the health of patients, because the reduction in muscle mass and muscle strength is also a cause of cardiometabolic disorders, such as myocardial infarction and stroke, and other adverse health outcomes (5, 7–9). For these reasons, it is of primary interest to find weight loss strategies that promote preferential loss of FM and preservation of muscle mass and its functional status (i.e., muscle strength) (10–12).
Children who discontinue the diet after achieving seizure freedom have about a 20% risk of seizures returning. The length of time until recurrence is highly variable, but averages two years. This risk of recurrence compares with 10% for resective surgery (where part of the brain is removed) and 30–50% for anticonvulsant therapy. Of those who have a recurrence, just over half can regain freedom from seizures either with anticonvulsants or by returning to the ketogenic diet. Recurrence is more likely if, despite seizure freedom, an electroencephalogram shows epileptiform spikes, which indicate epileptic activity in the brain but are below the level that will cause a seizure. Recurrence is also likely if an MRI scan shows focal abnormalities (for example, as in children with tuberous sclerosis). Such children may remain on the diet longer than average, and children with tuberous sclerosis who achieve seizure freedom could remain on the ketogenic diet indefinitely.[46]
It seems strange that a diet that calls for more fat can raise “good” cholesterol and lower “bad” cholesterol, but ketogenic diets are linked to just that. It may be because the lower levels of insulin that result from these diets can stop your body from making more cholesterol. That means you’re less likely to have high blood pressure, hardened arteries, heart failure, and other heart conditions. It's unclear, however; how long these effects last.
×