This study compared successful with unsuccessful participants and their mothers 1.5 years following completion of an immersion programme for the treatment of adolescent obesity. Teenagers (M age = 14.5; 69.5% female) participated in a 4- to 8-week therapeutic camp; those who continued losing weight 1.5 years post-camp were identified as ‘Losers’; those who regained weight were considered ‘Gainers’. Twenty-six Loser campers, 23 Gainer campers and all mothers were interviewed about their current weights and lifestyle habits. Losers' and Gainers' mothers both reported losing weight significantly. Relative to Gainer mothers, however, Loser mothers reported 26% fewer high-fat foods in the house and greater likelihood of self-monitoring. Loser campers, relative to Gainer campers, reported self-monitoring more consistently; using trainers more frequently; and consuming fewer calories and less fat. Gainer campers also reported a tendency to use family therapy more than Loser families. The Loser campers reported following the dictates of the programme more than the Gainer campers, as expected. One striking and unique finding, however, was that Gainer mothers seemed to follow the programme for themselves as much as Loser mothers. Apparently for some participants in immersion treatment (like the Loser campers in this study), parents who participate fully may promote sustained success; for other adolescent weight controllers (like the present Gainer campers), having ‘Do as I do’ mothers clearly does not guarantee sustained changes in lifestyle for the teenagers. A hypothesis based on these results is that additional cognitive-behaviour therapy subsequent to immersion may be useful for this latter group.