It’s like saying something is 100 calories and that therefore, you can 10 of that thing and be at 1000 calories. A lot of people who struggle with weight will believe that if a certain food is low calorie, vegan, or fresh, that you can eat as much of it as you want. They forget that you have to actually portion things out even if it’s considered a “healthier” option. I think the best course for someone really fat to lose weight would be to cut out any sugary drinks and eat foods with less sugar in them and substitute the lack of sugar for slightly higher fat intake and high protein. In theory, it would be easy to lose weight through this, but in practice, there would need to be someone there to help reinforce better eating behaviors if the food problems are severe enough. Also, learning to cook healthy food and shop for it would greatly improve chances of losing weight as well.