In individuals with moderate body fat percentages, fat loss can occur without concurrent muscle loss.

Study: Effects of Calorie Restriction With and Without Strength, Endurance or Mixed Training on Fat-Free and Skeletal Muscle Mass in Overweight or Obese Individuals-A Systematic Review With Pairwise Meta-Analysis and Network Meta-Analysis of Randomized Controlled Studies.

The study shows that when people diet and exercise, they still lose some muscle, just less than if they only diet. So losing fat without losing any muscle is not what usually happens.

Study: Resistance training volume does not influence lean mass preservation during energy restriction in trained males

The study found that people who cut calories and lifted weights still lost some muscle along with fat, which suggests that losing fat without losing any muscle is difficult and did not happen in this study.

Study: Effect of diet‐induced weight loss on muscle strength in adults with overweight or obesity – a systematic review and meta‐analysis of clinical trials

When people with extra weight lose fat by eating less, they often also lose some muscle strength — meaning their muscles get weaker, even if they didn’t mean to. So, it’s hard to lose fat without also losing some muscle power.