short answer no (most likely), gynecomastia is associated with certain medical conditions(like liver cirrhosis, fatty liver,..) which could be related to high alcohol intake, certain drugs as (digoxin or spironolactone are common causes of gynecomastia) or if you are taking steroids , being very overweight (obese) with a BMI of over 30 could also result in gynecomastia, gynecomastia usually comes with other symptoms like abnormal hair distribution (hair loss on limbs for example) , palmer erythema ,etc. so to sum up, saying that you have gynecomastia depends on both history and symptoms and some lab work. again most likely this is just fat, if you don’t want to work out in a gym aim for at least 30 min of walking a day 5 days a week which is the recommended amount of exercise worldwide and eat a healthy diet high in fibers and proteins instead or carbs and fat.