Final answer:
The best way to increase the proportion of lean body tissue is through regular resistance training or lifting weights.
Step-by-step explanation:
The proportion of lean body tissue can best be increased by engaging in regular resistance training, such as lifting weights. A balanced diet is important for maintaining good health, but when it comes to building lean muscle, consistent resistance training is a critical factor. This type of exercise stimulates the deposition of more bone tissue and muscle mass, which can be particularly beneficial for those looking to improve their physique or for athletes in sports where strength is an advantage. Additionally, resistance training plays an important role in preventing osteoporosis and managing bone density as one ages.