Obesity management is a big challenge for health care providers. Obesity-related metabolic diseases are the most common chronic conditions and risk for shorter lifespan. Primary care is the appropriate level, not only for the management but for the prevention and early recognition as well. Obesity develops gradually and needs attention in the early phase of weight gain. The main results of four Hungarian and international studies in primary care settings were summarized, seeking relationship between weight gain in younger life and development of metabolic diseases. Data of primary care patients were collected about the changes of their weight gain from 20y to the present. Source: medical files and self-reports. Early weight-gain between 20y and 30y means a serious risk for developing diabetes, between 30y and 40y for hypertension and even faster weight-gain could be a risk factor for both metabolic diseases. In females, significant weight gain around pregnancies and the menopause could increase the risk of these morbidities as well. Primary care service providers/family physicians/general practitioners ought to be not only an inactive observers, they have to give more focus on those of their patients who show conspicuous weigh gain in their younger decades, to explore the individual reasons and to initiate the appropriate intervention as early as possible.