American Journal of Business and Operations Research AJBOR 2692-2967 2770-0216 10.54216/AJBOR https://www.americaspg.com/journals/show/1097 2018 2018 Department of Computer Sciences - IBADAT International University Islamabad, 44000, Pakistan Raja Habib Department of Dietetics and Nutritional Sciences - IBADAT International University Islamabad, 44000, Pakistan Asra Touqir Department of Management Sciences - IBADAT International University Islamabad, 44000, Pakistan;Department of Mathematics and Statistics, Central South University Changsha, Hunan, China Irsa Sajjad Adults have a variety of experiences with social pressure to have low weight. Thus, there is a desire to lose weight with a variety of efforts, such as fad diets. This type of diet can lead to insufficient intake of nutrients in the body and increase the risk of health problems in the long run. The research aimed to analyze fad diets, BMI, and activity levels of adults in Islamabad. The research design was cross-sectional in 50 adults aged 19–58 years who were selected by simple random sampling. The data of fad diets used in the questionnaire, BMI data using the calculation of the last body weight and height, and activity level were measured using food frequency questionnaire. Data analysis used the chi-square test. The results of this research showed that most respondents implement fad diets (56%), had normal BMI (60%), had fairly activity levels (32%), while overweight BMI (34%), and obese (4%) of BMI, and had moderate and inactive activity level (26%). There was an insignificant (p =.085) correlation between fad diets and age (r = -.232), and in addition, there was an insignificant correlation (p =.171) between fad diets and BMI (r =.013). It is concluded that the adults who implemented fad diets and below normal tended to not have activity levels of BMI because of improper food selection and psychological factors. Adults are expected to be able to conduct weight loss with the assistance of a nutritionist or in accordance with balanced nutrition guidelines. 2022 2022 56 62 10.54216/IJNS.060206 https://www.americaspg.com/articleinfo/1/show/1097