This study examined the long-term effects of a lifestyle modification program delivered at German Bundesliga football clubs. Weekly 90-minute group sessions over 12 weeks combined health education and physical activity and were delivered by coaches affiliated with the football clubs. A total of 371 men (mean age 49.7 years [SD = 7.6]) attended 41 classes at 19 clubs in 2017 and 2018 and participated in the long-term follow-up. Primary outcome was weight-loss at follow-up with a mean observation period of 20.4 months after baseline. Measures were taken partly by research staff and partly by participants themselves. At baseline, the men had a mean weight of 111.3 kg (SD = 16.9). Three months after baseline (posttest), the men had lost a mean of 6.3 kg (95% CI: 5.7-6.9). From posttest to follow-up, growth curve model showed men lost an average of 0.8 kg (95% CI: 0.2-1.4). Weight regain from posttest to follow-up of at least 3% was observed in 75 participants (20.2%) and was associated with less improvement in vegetable consumption in an adjusted logistic regression model. The data suggest that participation in a male-only lifestyle modification program offered by German football clubs may lead to sustained weight loss, but lack of a randomized control group and drop-outs prevent generalization of the results.