Yukendu is a personal mobile coaching service that supports people in reaching good levels of psychological and physical wellbeing through the use of an app and a telephone-based relationship with a health coach. The aim of this contribution is to describe the results obtained in a sample of 171 clients (female, n=150) and investigate the main factors in attaining their health-related goals. Results show that 61,98% (n=106) of the sample attained the results they wanted totally or partially. The regression model (number of phone calls, text messages, plan duration, achieved weight loss) accounts for 56,9% of data variance in achieved weight loss. Significant predictors of achieved weight loss are average number of calls (B=.388, p<.05), texts exchange (B=.331, p<.05) and plan duration (B=.291). These results suggest therefore that in the first phase of health behavioral change, eHealth coaching efficacy lies primarily in the communication between coach and coachee.