Abstract—Weight gain may increase blood pressure. Weight loss may reduce this. Reviews have considered the long-term effects of weight loss but are related mainly to more obese participants often on obesity medication and/or undergoing obesity surgery. This systematic review, based on lifestyle interventions for adults (18 to 65 years) with mean baseline BMI of <35 kg/m², links weight change to blood pressure difference. A systematic review of studies reporting weight differences and blood pressure outcomes, published between 1990 and 2008 with follow-up of 2 years identified 8 clinical trials or controlled before and after studies (represented by 9 articles) and 8 cohort studies. Differences ranged from -11 to +4kg for weight, -7 to +2.2 mm Hg for diastolic blood pressure and -13 to +6.1 mm Hg for systolic blood pressure. For this population group, no quantifiable relationship between weight and diastolic blood pressure difference was found, possibly because of small weight losses, differing weight status responses, or because pharmacologically controlled hypertension masked weight loss influences. Systolic differences were in line with previous reviews of 1 kg:1 mm Hg relationship, but only for follow-up periods of 2 to 3 years, possibly reflecting the fact that regardless of maintained weight loss, blood pressure often reverts back to higher levels. Lifestyle interventions for weight and blood pressure are limited in this target group, and there has been no exploration of successful intervention components. An individual patient data analysis may uncover baseline and medication effects, explore differences between weight groups, and may identify successful components. Such an analysis would enable effective development of preventative interventions for both hypertension and obesity.