The present study will carry out a workplace health promotion via MBI with lessons of dietary behavior to help overweight or obese workers to loss weight.

The study will adopt a longitudinal research design with randomized quasi- experimental trial. The workers with overweight or obesity (BMI≧24) provided by the company will be randomly assigned to Group A (four lessons of dietary behavior and six lessons of MBI) or Group B (four lessons of dietary behavior and six lessons of mental health). There will be 100 participants in each group. Data will be collected five times. The research questionnaire includes basic information (including BMI, waist circumference, etc), Perceived Stress Scale, The Five Facet Mindfulness Questionnaire, Food Cravings Questionnaire, the scale of physical activity and information regarding dietary behavior.

Inclusion Criteria:

1. adults aged 20 to 65 years old;
2. full-time workers with BMI ≧ 24;
3. motivated to participate in the study;

Exclusion Criteria:

1. suffering from mental illness or in an acute episode;
2. suffering from life threatening or other major physical illness;
3. no motivation to participate in the study.

The researchers will explain the purpose and steps of the study to all the participants and get their informed consent.