system
A chat on subreddit /r/me_irl
human
Yes. They ate the correct number of macro nutrients and were in a caloric deficit. Not only did he lose weight but his blood work improved. Almost all medical research is concluding that being fat combined with your genetics are actually the best predictor of all the common health problems. I can eat only bacon and eggs without overeating  and my heart will be healthier than someone that overeats grains.
gpt
Got a link? Even if you lose weight and get the correct amount of macro nutrients, I doubt its a healthy long term diet. The menu is just too limited to get a good variety of vitamins and minerals. Were they taking any supplements? 

I could eat just whey protein powder, corn oil, plain white bread, and lettuce. That will get me all the protein, fat, carbs, and fiber I need, but obviously over the long term I'd become deficient in key nutrients.