Final answer:
The statement is true; ideal body weight varies due to factors such as sex, age, and lifestyle, and is also influenced by societal standards. Body composition is key for athletes' performance and can be misleadingly represented by BMI, which does not account for muscle mass.
Step-by-step explanation:
The statement 'No single body composition or weight suits everyone; needs vary by gender, lifestyle, and stage of life.' is true. Ideal body weight (IBW) and body composition are influenced by a variety of factors including frame size, sex, muscle mass, bone density, age, and height. Additionally, these factors are also influenced by cultural perceptions and societal standards. It's also important to recognize that body weight and composition can significantly affect exercise performance and can be altered through diet and training, especially in athletes. Furthermore, measures like Body Mass Index (BMI) can sometimes be misleading as they only consider height and weight, not accounting for muscle versus fat content, thus not providing a full picture of an individual's health.