I have seen people get great results from a ketogenic diet plan. A keto or ketogenic diet is a very low carbohydrate, moderate protein, high fat diet, causing the body to produce fat from the liver called ‘ketones’ and relying on it as the primary energy source for fuel (ketosis). It has been shown to have benefits for weight loss, health and performance. If you have been eating a diet based heavily on processed foods, flours and sugars, then you are surely guaranteed to get results, at least initially. But to have this diet work for you in the long term, you need to avoid these pitfalls.
Even on a ketogenic diet, your fat choices matter. I have seen people on the Internet who view it as an opportunity for an all-you-can-eat pork, cream and lard fest. Regardless of whether you are holding up your fat ratios, the types of fat that exist in these foods aren’t healthy choices when consumed in such large quantities, unless you want to see your blood pressure sky rocket in record time. Use animal fats in moderation and emphasize getting your fats from different types of cold water fish (salmon, cod, mackerel) or from avocados, nuts, seeds, and olive oil, etc.
Eating too much protein on a ketogenic diet is the #1 error I see people make on this diet. Ordinarily, I encourage people to up their protein intake, but doing this on a ketogenic diet is a mistake because you are relying on ketones for fuel. Protein (amino acids) can be turned into glucose through the liver (gluconeogenesis). So if you are eating too much protein, you end up using that fuel as stored glucose which makes maintaining a state of ketosis much more difficult. Keep your protein intake to no more than 25% of your total calorie intake per day.
Continue to watch your total calorie intake. Fortunately, ketogenic diets are very efficient at curbing your appetite once your body has adapted to them. So if you are suffering from the illusion that you are eating as much as you like without adding pounds, in actuality you are just satisfied with less food and ingesting less calories. There is a marginal metabolic advantage to eating a ketogenic diet, because you can eat a few extra calories without gaining fat, but it is not nearly enough to justify a daily all out binge. If you ingest significantly more calories than you use on a daily basis, you will gain weight.
If you want your ketogenic diet to work, avoid trying modified versions of this diet that you will run across on the Internet. The most popular one I have seen is where one high carbohydrate day a week is added to the plan. The idea being that you stay in ketosis for 6 days of the week and then you refuel with large portions of carbohydrates on the 7th day. The logic behind it is that if you are extremely active you will want to replenish your glycogen stores after a significant time with only a trace amount of carbohydrates in your system to improve overall performance. The problem with this approach is that a significantly high carbohydrate meal (100 g or more) will decrease ketone production for the next 2 to 5 days thereafter. So you end up spending the remainder of each week attempting to re-establish what you started at the beginning of the week.
Even though these modified diets can work equally well for fat loss, you will end up feeling like garbage after the high carbohydrate day, and the carb cravings that accompany them the rest of the week make adherence to the diet extremely difficult. If you are going to attempt a ketogenic diet to improve your health and well being, you need to approach it as a lifestyle change, not just something you do a few days a week. Best of luck!