human 205 female 155 Humans 149 male 142 adult 116 income 105 Article 101 Female 94 Male 89 major clinical study 88 controlled study 74 article 64 Adult 63 middle aged 59 household income 58 Income 56 child 52 United States 51 Middle Aged 48 aged 48 middle income country 45 lowest income group 44 cross-sectional study 43 adolescent 42 poverty 41 income distribution 38 questionnaire 36 Adolescent 35 Poverty 34 Aged 33