In my experience it is more difficult for smaller women to lose weight (and maintain).
Take a man that wants to lose weight that is 6'1 and 250 lbs, reduce his total calories by 20% and you have a 700 calorie deficit. He can eat 2800 calories per day and still theoretically lose 1.4 lbs per week.
Take a woman that wants to lose weight that is 5'0 and 150 lbs, reduce her total calories by 20% and you have a 340 calorie deficit. She must eat 1360 calories per day to lose only 0.7 lbs per week. Yet they both have the same relative 20% calorie reduction.
That is less than half of what the man can eat and still lose weight. Naturally, smaller women will eat less and become full faster. But the problem arises with restaurant food, calorie dense food, and "empty calories" like soda or coffee drinks. All these foods are easy to over-consume and portion sizes are not designed for these women.
The average restaurant meal in America is near 1200 calories. The women eats 1360 calories TOTAL per day to lose weight. That doesn't quite pencil out does it? Haha.
And what about slip-ups? Everyone messes up from time to time. Say they each cave for a small milkshake that has 700 calories. Assuming all else is normal, the man will not lose any weight that day. The woman, however, will not lose weight that day and it will take the entire next day of perfect eating to make up for the overage.
Sorry to my petite ladies, such is the reality of fat loss. 🤷♀️ If you go out to eat with your larger spouse or partner, you have to be much more careful. And even little things like licking the peanut butter off the spoon can add up to make it seem like your diet isn't working.