It's normal. There are too many such people in life, especially female friends. First of all, when she said to lose weight, she really meant it. Being thin is an important criterion for women to pursue beauty today. Many women want to be thin and have a good figure, but many people talk about losing weight, some people do what they say, some people just talk about it, and some people are struggling on the road to losing weight.
Secondly, maybe your friend is really losing weight. Shut up and spread your legs is a good way to lose weight, but losing weight doesn't mean you can't eat delicious food. Your friend's weight loss can be exercise. She makes great efforts in fitness. While pursuing a perfect figure, she might as well pursue food. Single food may make the road to weight loss more difficult.
Finally, the circle of friends is very wide, and many people use this platform to show off themselves. Your friend may just want to bask in the sun on weekends. Many people take pictures, but they don't really eat, and so do many female stars.
Of course, your friend knows her well, so you don't have to care too much about her behavior, and treat her with a normal heart.