The 80/20 rule suggests that most results (around 80%) come from core habits, while a smaller portion (20%) comes from fine-tuning. In weight loss, this means calorie balance, protein intake, daily movement, and sleep drive the majority of progress. A “perfect” plan is less effective than a good plan you can sustain. The 80/20 approach also supports flexibility: most of your diet comes from nutrient-dense foods, while a smaller portion allows for enjoyment. This flexibility improves long-term adherence and overall success.