Psychological well-being and hunger and food control are two relevant factors involved in the success of weight-loss therapy in treating obesity. Thus, this study aims to evaluate food and alcohol cravings, physical and sexual activity, sleep, and life quality (QoL) in obese patients following a very low-calorie ketogenic (VLCK) diet, as well as the role of weight lost and ketosis on these parameters. A battery of psychological test was performed in twenty obese patients (12 females, 47.2 ± 10.2 year and BMI of 35.5 ± 4.4) through the course of a 4-month VLCK diet on four subsequent visits: baseline, maximum ketosis, reduced ketosis, and endpoint. Each subject acted as their own control. Relevantly, the dietary-induced changes in body composition (7.7 units of BMI lost, 18 kg of fat mass (1.2 kg of visceral fat mass)) were associated with a statistically significant improvement in food craving scores, physical activity, sleepiness, and female sexual function. Overall, these results also translated in a notable enhancement in QoL of the treated obese patients. Therefore, the rapid and sustained weight and fat mass (FM) loss induced by the VLCK diet is associated with good food control and improvements in the psychological well-being parameters in obese subjects, which could contribute to the long-term success of this therapy.

I get many questions about intermittent fasting, the health benefits, the weight loss benefits, and the like. People normally use intermittent fasting for both the energy and mental clarity it can offer. But it’s not just good for that. It can offer breakthroughs of plateaus and even benefits in nutrient uptake in exercise. We go more in depth to intermittent fasting in Week 3 and 4, so keep your eyes peeled!
The popular low-carb diets (such as Atkins or Paleo) modify a true keto diet. But they come with the same risks if you overdo it on fats and proteins and lay off the carbs. So why do people follow the diets? "They're everywhere, and people hear anecdotally that they work," McManus says. Theories about short-term low-carb diet success include lower appetite because fat burns slower than carbs. "But again, we don't know about the long term," she says. "And eating a restrictive diet, no matter what the plan, is difficult to sustain. Once you resume a normal diet, the weight will likely return."
Thyroid health and longevity. Along with balancing sex hormones, a ketogenic lifestyle has a positive effect on thyroid hormones as well. A very low-carb diet tends to drive down T3, the main active thyroid hormone. Higher T3 levels make your cells use more energy (hyperthyroidism), which can increase free-radical production. Many scientists believe that lower levels of T3 actually increase lifespan by conserving energy and decreasing free-radical production. A ketogenic lifestyle is positively correlated with improved thyroid health and overall longevity [15].

While you’re focusing on fat, protein, and carbs, you should also make sure you’re getting adequate fiber. “People often assume that they should only eat things like meat and butter on the ketogenic diet,” says Farshad Fani Marvasti, MD, an associate professor and director of Public Health, Prevention, and Health Promotion at the University of Arizona College of Medicine in Phoenix. “You should make sure you are eating enough vegetables because you need the fiber.”
Participants were recruited from the Durham Veterans Affairs Medical Center (VAMC) outpatient clinics. Inclusion criteria were age 35–75 years; body mass index (BMI) >25 kg/m2; and fasting serum glucose >125 mg/dL or hemoglobin A1c >6.5% without medications, or treatment with oral hypoglycemic agents (OHA) and/or insulin. Exclusion criteria were evidence of renal insufficiency, liver disease, or unstable cardiovascular disease by history, physical examination, and laboratory tests. All participants provided written informed consent approved by the institutional review board. No monetary incentives were provided.
The ketogenic diet may seem like the Jekyll to the Hyde-like low-fat craze of the 1990s. The bulk of current research finds that the middle ground between the two extremes is more beneficial for overall health. Make it easy for yourself: Eat at least two servings a week of fatty fish (salmon, sardines, mackerel) and cook with a variety of quality fats (olive oil, canola oil, avocado oil) throughout the week.
Boosts energy levels. The sluggishness and lethargy you feel after a heavy carb-filled meal is due to the insulin spike and reactive sharp drop in blood sugars. Eating a high-fat diet provides steady energy and helps you avoid crashes that are associated with eating a high-carb diet. Additionally, since ketones are the brain’s preferred source of energy, a ketogenic diet leaves you feeling more alert and mentally energized without having to supply a steady stream of caloric intake [13].
This work demonstrates that a VLCK diet following the PNK method induces a severe body weight reduction concomitantly with a decrease in food craving and improvements in psychological well-being measured by physical activity, sleep quality, female sexual function, and quality of life scores. The effect in food craving and psychological well-being could be relevant factors to guarantee the success of this kind of nutritional treatment. Moreover, this effect is added to the beneficial effects previously observed regarding body composition, energy metabolism, and biochemical parameters [4,7,18,35].
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.