The best thing one can do to start a weight loss plan is have his resting metabolic rate checked. Everyone has a different rate. While people say it is simple math, it isn't the same math for each person. The guy that is always gaining weight even though he eats a very similar diet to his skinny buddy and they work out together daily has a slower metabolic rate (BMR). In order for him to lose weight he needs a better idea of his baseline. Some people have a a BMR of 700 calories per day and some are at 2300 calories per day. That is huge difference.
Counting calories is the best option because you can use a diet plan tailored to your BMR. If you have a BMR of 1000, a desk job and don't workout, you need to eat 1200-1500 calories to lose weight. Meanwhile, the guy with the 2300 BMR is literally starving to death.
BMR can be tested by doctors with the right equipment. There is a machine that you breathe into for about 10 minutes and it calculates calories being burned by the contents of your exhaled breath.
There was a doctor that put his weight loss patients on a 1200 calorie diet and kept them contained in his clinic for a long period of time. 1200 calories seems to be the magic number for men and women to lose weight no matter their BMR. Most men will succeed on 1500 calories as well. The doctor was asked what he could do for the people that still fail to lose weight even on a 1200 calorie diet. He said, " I've never come across anyone that doesn't lose weight on a 1200 calorie diet". The key is counting calories, if you don't lose weight at 1200, you are probably fudging the numbers. The issue is, that it takes a great deal of will power for people with a strong appetite to eat so little.
People cursed with a slow metabolism tend to feel hungry all the time and lack the energy to work out. That is typical of people with metabolic syndrome. They can't do what naturally thin people do. It doesn't work. Thin people that view overweight people as pigs that eat too much are completely ignorant to the biological reasons for it. Of course, lots of people have terrible eating habits and are fat because they eat terrible stuff. But at least half of people eat totally normal, healthy diets and are still obese.
Keto diets with high fat, high protein don't work for everyone, only people that handle it well. High fat causes weight gain in some people, just as high carb does in others. Different body types.
Another mind blower. Brown rice is likely less healthy than white rice. It has tons of phytic acid which blocks nutrient absorption, irritates the stomach and can cause inflammation.
This all brought to you by someone that eats 2000 calories per day, works out 4 times per week and never stops tinkering with it. I maintain a healthy weight based on the numbers but until I knew my BMR, it was way harder. Definitely worth getting the test done as is counting calories.
Also, if you go to a restricted calorie diet, you'll find that protein is what keeps you burning calories. 20g-30 of protein every 2-3 hours will usually keep the metabolism going. Protein shakes with low carbs and sugar and about 150 calories per shake are ideal.