Your experience is not universal. Many classes of obesity CANNOT be treated by “eating apples”. Don’t just take my word for it:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5764193/ (2019)
Substantial weight loss is possible across a range of treatment modalities, but long-term sustenance of lost weight is much more challenging, and weight regain is typical1–3. In a meta-analysis of 29 long-term weight loss studies, more than half of the lost weight was regained within two years, and by five years more than 80% of lost weight was regained (Figure 1)4. Indeed, previous failed attempts at achieving durable weight loss may have contributed to the recent decrease in the percentage of people with obesity who are trying to lose weight5 and many now believe that weight loss is a futile endeavor6.