Obviously it is used to describe professional bodybuilders, but now it is often used to emphasize the importance of diet to beginners. If that's all, it's true. The importance of diet for fitness is obvious to all.
If your goal is to lose fat, whether you eat too much or eat inappropriate food, it's probably all for nothing. If your goal is to gain muscle, and you don't get enough protein and calorie support, it's even harder to practice to a certain dimension.
So there is nothing wrong with the meaning of this sentence. In order to achieve the best effect of fitness, diet is very important. But the problem is that using a three-part numerical comparison model to emphasize diet can easily mislead beginners into thinking that training only affects 30% of their grades. But the reality is that if you want the best results, everything is important, and ignoring any point will lead to slow progress.
Nutrition is not as important as training. Muscle is a highly adaptable tissue. If you want muscle growth, you must give it a good reason, and this reason is not diet. Although diet is essential for reducing fat, it is training that helps to grow and maintain muscles. Muscle is the main driving force of metabolism, and you can't eat muscle without training.
Without hard training, a perfect diet will never produce results, and hard training based on improper diet will not bring the greatest progress. Eating and training can't be divided by percentage. If it must be expressed by numbers, please remember that Dorian Yates once said, "Nutrition accounts for 100%, training accounts for 100%, and recovery accounts for 100%."