Keto, Atkins and other Diets fall into that fallacious reasoning category called "fad diets." These usually result in some quick weight loss of perhaps around 20 pounds, usually all water. And then later, the people who try them gain back the weight and more because the body reacts to a sort of starvation that it seeks to counter by storing up more fats than ever. That's how the fad diets fail. It's almost better to avoid dieting all together, or so it would seem.
The best and most successful diets are by the numbers, call them 'Numbers Diets', the numbers being calorie counts. The proper name then would be Calorie Count Diets.
Calories are constantly being burned in the human body, even when resting. Exercise burns more calories, of course. Calories are added by the foods and beverages the body takes in. In most people, the at rest weight will remain constant, despite the intakes and burns. This is because the body regulates its weight.
When the body experiences starvation, it reacts by adjusting that at rest weight - upwards.
What that indicates is that weight loss should not even be attempted to be an 'as much as can be done' race. It must be subtle and slow paced, but steadily downward. This ensures that the body is not shocked by what it senses as starvation. This is the best advice for weight loss.
How does one do Calorie Count regulation?
First, it doesn't really matter what you eat. What matters is the adjustment in calories burned and calories taken in. Therefore, you can eat from all the food groups and get a healthy intake.
Second, you need to calculate your 'at rest' normal Calorie Burn. This is the magic number of Calories that your body burns when it is doing nothing special in terms of additional exertion. You can look into things like Body Mass Index (BMI) on your own, but tables exist for Adults and Children based on Age, Height and current Weight.
Third, you need to make adjustments. These are planned adjustments and not just random. You increase your Calorie Burn with more exercise and decrease you Calorie Intake by choosing the foods and amounts that you eat. You need to keep Calorie Logs, both for your regulation and references for the Calories in the foods you eat.
IMPORTANT! Remember not to make it a race, pitting yourself against some overly ambitious attempt to loose large amounts of weight quickly. Don't weight yourself daily. Do it monthly so that you can see a difference, but aren't in a frenetic race to loose large amounts of weight. Do NOT shock your body in a way that it will sense starvation. Make your weight loss gradual and slow, but sure.
It is important to understand that a successful diet, by the numbers, requires some behavioral changes. Habits need to be broken. Some of those eating habits are deep rooted psychologically. But none-the-less, the habits need to be modified to be successful. It may be necessary to be continuous in your monitoring of your Calorie adjustments, for a long time - years.
Good Luck!