Limit liquid calories. Soft drinks may be the most popular beverages at a barbecue, and just one soda can add 150 to 200 calories to your daily tally. Have a few glasses throughout the day and youre talking about enough extras to make the difference in weight loss or gain. Even lemonade and iced tea (if sweetened with sugar) can add up. Stick to water, diet soda or another calorie-free beverage.