Gaining weight may be a common desire for many people who wish to boost their overall health and fitness levels. However, using the same phrase repeatedly can sound monotonous and dull. Fortunately, there are numerous creative alternatives one can use when describing the process of gaining weight. Some synonyms that can be used instead of "gain weight" include putting on weight, increasing mass, adding pounds, building body fat, and packing on the pounds. Other phrases that can be used are beefing up, bulking up, and getting thicker. Understanding the various alternatives to gain weight will help make expressing this interest more enjoyable and engaging.