Examination of whether early weight loss predicts 1-year weight loss among those enrolled in an Internet-based weight loss program.

One-month weight loss (WL) predicts posttreatment WL in face-to-face interventions; however, whether this holds true within Internet programs is unknown. This study examined whether 4-week WL predicts WL following a 12-week Internet program and at 6 and 12 months follow-up. A total of 181 participants (body mass index=33.4±5.5 kg m(-)(2); 83.1% female) received a 12-week behavior-based Internet WL program consisting of weekly video lessons. Participants were given a daily WL, calorie and physical-activity goal and asked to enter these data on the study website weekly. Personalized feedback was provided. Using 4-week WL, individuals were categorized as 'early nonresponders' (<2.0% WL) or 'early responders' (⩾2.0% WL). Early nonresponders had significantly lower WL than early responders at 3 (-1.3±3.8% vs -6.3±4.3%), 6 (-1.7±5.1% vs -5.8±5.2%) and 12 months (-0.05±6.8% vs -2.7±6.3%, P<0.05). The odds of achieving a ⩾5% WL were 8.5 (95% confidence interval (CI), 3.3-22.1), 3.4 (95% CI, 1.4-8.3) and 2.6 (95% CI, 0.93-7.4) times lower in early nonresponders, compared with early responders at 3, 6 and 12 months, respectively. Compared with early responders, early nonresponders viewed fewer video lessons and self-monitored less often across the 12-week intervention (P<0.05). This study provides initial evidence that a 4-week WL of <2.0% places an individual at an increased risk of failing to achieve clinically significant WL following an Internet program.