1. Fat Loss
Keto proponents state ketogenic or low carb diets are superior for fat loss than other stratagems:
- A common, albeit inaccurate, axiom in nutrition is that a calorie is a calorie (i.e., the distribution of macronutrient has no effect independent of total energy). In respect to body composition, convincing evidence of the importance of macronutrient composition was presented in a comprehensive meta-regression of 87 diet trials (10). The authors concluded that diets lower in carbohydrate were associated with greater fat loss and diets higher in protein resulted in better preservation of lean body mass during weight loss. Furthermore, these effects were independent of energy intake and participation in exercise.
We have consistently shown in our work that very low carbohydrate ketogenic diets result in greater weight loss and fat loss compared with low-fat diets. In overweight men and women, we have repeatedly observed a 2-fold greater weight loss and fat loss in subjects restricting dietary carbohydrate versus fat despite similar caloric restriction between the diets
- Individuals assigned to a VLCKD achieve a greater weight loss than those assigned to a LFD in the long term; hence, a VLCKD may be an alternative tool against obesity.
- Diets that reduce caloric intake result in weight loss. In the absence of physical activity, a diet that contains ∼1400 to 1500 kcal/d, regardless of macronutrient composition, results in weight loss. Individuals consuming high‐fat, low‐CHO diets may lose weight because the intake of protein and fat is self‐limiting and overall caloric intake is decreased (11,12). Low‐fat and VLF diets contain a high proportion of complex CHOs, fruits, and vegetables. They are naturally high in fiber and low in caloric density. Individuals consuming these types of diets consume fewer calories and lose weight (13–17). Balanced nutrient reduction diets contain moderate amounts of fat, CHO, and protein. When overall caloric intake is reduced, these diets result in loss of body weight and body fat (6,18). Importantly, moderate‐fat, balanced nutrient reduction diets produce weight loss even when they are consumed ad libitum.
- The apparent paradox that ad-libitum intake of high-fat foods produces weight loss might be due to severe restriction of carbohydrate depleting glycogen stores, leading to excretion of bound water, the ketogenic nature of the diet being appetite suppressing, the high protein-content being highly satiating and reducing spontaneous food intake, or limited food choices leading to decreased energy intake. Long-term studies are needed to measure changes in nutritional status and body composition during the low-carbohydrate diet, and to assess fasting and postprandial cardiovascular risk factors and adverse effects. Without that information, low-carbohydrate diets cannot be recommended.
- There is a substantial body of evidence indicating that low-carbohydrate diets are effective for weight loss. With the exception of a study of severely obese patients, body weight and waist circumference were reduced among all of the low-carbohydrate dietary intervention studies, with mean reductions ranging from 1.5 to 14.3 kg and from 2.2 to 9.3 cm, respectively. Our findings suggest that low-carbohydrate diets are at least as effective as low-fat diets for weight loss, regardless of gender, age, length of intervention, diabetes status, and level of carbohydrate restriction.
- Trials show weight loss in the short-term irrespective of whether the diet is low CHO or balanced. There is probably little or no difference in weight loss and changes in cardiovascular risk factors up to two years of follow-up when overweight and obese adults, with or without type 2 diabetes, are randomised to low CHO diets and isoenergetic balanced weight loss diets.
- Ketogenic diets can help patients lose about 2 kg more than low-fat diets do at 1 year, but higher-quality studies show no difference. Weight loss peaks at about 5 months but is often not sustained. Individual weight change can vary from losing 30 kg to gaining 10 kg with any diet.
The studies show low carb ketogenic diets are at least as effective as other diets and calorie restriction for weight loss and may be superior in certain cases.
2. Health Effects
Mainly opponents of ketogenic diets state that it is bad for the health of the dieter and can cause an early death due to fat intake. Proponents state the opposite.
- The present study shows the beneficial effects of a long-term ketogenic diet. It significantly reduced the body weight and body mass index of the patients. Furthermore, it decreased the level of triglycerides, LDL cholesterol and blood glucose, and increased the level of HDL cholesterol. Administering a ketogenic diet for a relatively longer period of time did not produce any significant side effects in the patients. Therefore, the present study confirms that it is safe to use a ketogenic diet for a longer period of time than previously demonstrated.
- 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.
The ketogenic diet is contraindicated in patients with pancreatitis, liver failure, disorders of fat metabolism, primary carnitine deficiency, carnitine palmitoyltransferase deficiency, carnitine translocase deficiency, porphyrias, or pyruvate kinase deficiency.
- Keto can negatively impact athletic performance. However, Zach Bitter the American 100 mile record holder eats a ketogenic diet.
- A 12-week low-carbohydrate, high-fat diet improves metabolic health outcomes over a control diet in a randomised controlled trial with overweight defence force personnel.
There doesn’t seem to be hugely negative health effects such as fat making you fat and a high fat diet causing you to have an heart attack and die. However, this doesn’t mean the keto diet is 100% risk free and healthy or effective for everyone. Yet it doesn’t mean it will result in an horrific death for you either. If you are bulking up I don’t personally recommend it. If you want to get lean or maintain leanness it may be an effective diet for you.