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.
Recently, four studies have re-examined the effect of carbohydrate restriction on type 2 diabetes. One outpatient study enrolled 54 participants with type 2 diabetes (out of 132 total participants) and found that hemoglobin A1c improved to a greater degree over one year with a low-carbohydrate diet compared with a low-fat, calorie-restricted diet [5,6]. Another study enrolled 8 men with type 2 diabetes in a 5-week crossover outpatient feeding study that tested similar diets [7]. The participants had greater improvement in glycohemoglobin while on the low-carbohydrate diet than when on a eucaloric low-fat diet. The third study was an inpatient feeding study in 10 participants with type 2 diabetes [8]. After only 14 days, hemoglobin A1c improved from 7.3% to 6.8%. In the fourth study, 16 participants with type 2 diabetes who followed a 20% carbohydrate diet had improvement of hemoglobin A1c from 8.0% to 6.6% over 24 weeks [9]. Only these latter three studies targeted glycemic control as a goal, and two of these were intensely-monitored efficacy studies in which all food was provided to participants for the duration of the study [7,8]. Three of the studies [6,8,9] mentioned that diabetic medications were adjusted but only one of them provided detailed information regarding these adjustments [9]. This information is critical for patients on medication for diabetes who initiate a low-carbohydrate diet because of the potential for adverse effects resulting from hypoglycemia.
The ketogenic diet, or even just a higher-fat, low-carb diet, has now gained massive support as a modern-day healing strategy. In fact, our ideas about fats and cholesterol seem to have been almost completely reversed in recent years. That being said, many people see their cholesterol go up after beginning more of a ketogenic lifestyle. Some people get concerned when this happens, so in this article, I am going to address the phenomena of high cholesterol on a ketogenic diet.
There are vegetables that are high in carbs and others low in carbs. The keto diet recommends sticking to the ones low on carbs but encourages you to eat a lot of them. Best vegetables are all green ones to make it easy. And vegetables that grow above the ground (e.g. lettuce) are always better than the ones that grow below the ground (e.g. potatoes)