Which strategy is effective for achieving a calorie deficit?

The strategy of reducing portion sizes and increasing physical activity is effective for achieving a calorie deficit because it directly addresses the balance between calorie intake and caloric expenditure. By reducing portion sizes, an individual is likely consuming fewer calories at each meal, which contributes to a negative energy balance. Simultaneously, increasing physical activity raises the number of calories burned each day, further enhancing the calorie deficit.

When both of these strategies are implemented together, they create a synergistic effect that can lead to more significant weight loss over time. The combination not only helps in reducing excess body fat but also promotes overall health by encouraging physical fitness. This approach is consistent with the principles of weight management, which emphasize the importance of both dietary choices and physical activity in achieving and maintaining a healthy weight.

In contrast, other strategies such as increasing portion sizes or choosing higher-calorie foods would have the opposite effect by increasing caloric intake, making it more challenging to achieve a calorie deficit. Avoiding all forms of exercise would likewise reduce calorie expenditure, further hindering efforts to lower body weight.