Table 2.

Characteristics of included studies on the relationship between UPF consumption and risk of breast cancer.

Studies	Location	Study design	Total number of participants	Age	Exposure assessment	Adjustment or matched for in analyses	Outcomes
Fiolet et al. (18)	France	Cohort	82,159 (739 cases)	≥18 years	24 h dietary recall	Age (timescale), sex, energy intake without alcohol, number of 24 h dietary records, smoking status, educational level, physical activity, height, body mass index, alcohol intake, and family history of cancers, menopausal status, hormonal treatment for menopause, oral contraception, number of children and Western dietary pattern (derived by factor analysis).	Highest versus lowest categories of UPF consumption (HR = 1.14,95% CI: 0.91, 1.44); Hazard ratio for increase of 10% in proportion of ultra-processed food intake in diet (HR = 1.11, 95% CI:1.02,1.21)
Romaguera et al. (20)	Spain	Case-control	1,486 cases 1,652 controls	20–85 years	FFQ	Age, study area, educational level, body mass index, physical activity, smoking, hormone replacement therapy use, oral contraceptive use, family history of breast cancer, age at menarche, age at first pregnancy, number of children, menopausal status, total energy intake, and ethanol intake.	Increment of 10% of UPF in the diet increases the risk of breast cancer (OR = 1.07; 95%CI:1.00,1.15); Highest vs. lowest categories of UPF consumption (OR = 1.24, 95% CI: 1.03, 1.49).
Chang et al. (21)	United kingdom	Cohort	197,426 (3,030 cases)	40–69 years	24 h dietary recall	Age (underlying timescale), ethnicity, smoking status, physical activity level, average household income, highest educational attainment, alcohol intake, body mass index, total daily energy intake, and stratified by sex, height, family history of cancer, index of multiple deprivation quintile, geographical region, baseline menopausal status, use of oral contraceptives, use of hormone replacement therapy, and parity.	Per 10% increment in UPF intake (HR = 1.16, 95%CI:1.02, 1.32); Highest vs. lowest categories of UPF consumption (HR = 1.62,95% CI: 0.98, 2.68).
Kliemann et al. (22)	European countries	Cohort	450,111 (2,223 cases)	Mean age: 51 years	FFQ	Age at recruitment (in 1 year categories), center sex, smoking status and intensity, educational level, physical activity, height, diabetes, BMI, Mediterranean diet, alcohol intake, total energy intake, and total fat, sodium, and carbohydrate intakes at recruitment.	Highest vs. lowest categories of UPF consumption (HR = 0.99,95% CI: 0.96, 1.02); Per 10% increment in UPF intake (HR = 1.00, 95%CI:0.96, 1.04).
Romieu et al. (23)	Latin America	Case-control	525 cases 525 controls	20–45 years	FFQ	Age (±3 years), city district of residence and health insurance institution and adjusted for education, (≤primary/secondary/> secondary), moderate intensity physical activity (continuous), number of full-term pregnancies (continuous), age at first full-term pregnancy (nulliparous/<20; 20–25; ≥25), breast feeding ever (yes/no), BMI (continuous), total energy intake (continuous), energy intake from the other NOVA groups (NOVA 1, NOVA 2, NOVA 3 added simultaneously in the model)	Highest tertile of UPF consumption had 93% higher risk of breast cancer (OR = 1.93,95% CI: 1.11,3.35)
Jacobs et al. (24)	South Africa	Case-control	396 cases 396 controls	≥18 years	FFQ	Individual income per month, ethnicity, physical activity, waist circumference (not adjusted for waist circumference when stratified by obesity status) and menopausal status (not adjusted for menopause when stratified by menopausal status)	Highest tertile vs. lowest tertile of UPF consumption (OR = 1.03,95% CI: 0.72, 1.45).

BMI, Body mass index; CI, Confidence interval; FFQ, Food frequency questionnaire; HR, Hazard ratio; OR, Odds ratio; UPF, Ultra-processed food.