Table 2:

Evidence from studies directly assessing the association between UPF consumption and obesity or weight change among plant-based consumers.

Author	Country	Study design	N participant	Study population	Dietary intake assessment	Ultra-processed Food Classification	UPF Exposure estimation	Outcome-related Weight change/Obesity	NOS or CRB quality assessment
Kahleova et al.,(48)	United Staes	Randomized Control trial	244 participants	Overweight adults	Dietary records	The classification of ultra-processed foods was based on the NOVA classification system	UPF intake (g/day)	The randomized controlled trial involved the vegan group (avoid animal products and minimize oils) and a control group (No dietary changes). Reducing animal UPF led to weight loss: every 120 g/day decrease was linked to 1 kg weight loss over 16 weeks (p = 0.001). After adjusting for energy intake, every ~156–158 g/day reduction corresponded to 1 kg loss (p = 0.02)	Fair quality
Navratilova et al.,(47)	United Kingdom	Prospective Cohort	3342 self-reported Vegetarians	UK Biobank participants	self-administered 24-h recall questionnaire	The classification of ultra-processed foods was based on the NOVA classification system	% of energy from UPFs. This study directed evaluated the research question	Participants were categorized into two groups: vegetarian PBMA consumers and vegetarian PBMA nonconsumers. UPF intake was higher among PBMA vegetarian consumers vs. non-PBMA vegetarian consumers (46% vs 40%, p=0.001), and without adjustment, the distribution of body weight differed between the 2 groups (BMI 24.9 vs 24.2, p = 0.001). PBMA intake was not associated with obesity risk (RR = 0.88, 95% CI: 0.55–1.42, p = 0.60) after adjusting for confounding factors.	Good quality
Gehring et al. (41),	France	Cross-sectional	21212 participants men =26.9% and women 73.1%	The Nutri Net-Sante cohort age > 18y, included meat-eaters = 19,812, pes-co-vegetarians = 646, vegetarians =500, and vegans =254. Subsample without meat eaters =1400.	24-h dietary records (more than 3000 items): Completion of 3 non-consecutive 24-h dietary records for 1 weekend day and 2 weekdays. Validated by comparison with 24-hour urine and blood biomarkers	The classification of ultra-processed foods was based on the NOVA classification system. NOVA group 4 which includes plant-based meat and dairy substitutes. All food and beverages were reviewed by 3 dieticians and 5 researchers, specialists in nutritional epidemiology in 4 NOVA groups.	% of energy from UPFs.	UPF consumption was significantly higher for vegetarians (37%) and vegans (39.5%) than meat-eaters (33%), p<0.001. Across quartiles of UPFs consumption among the vegetarian subgroup (n=1400), vegetarians (β = 0.024, p=0.002) and vegans (β = 0.042, p< 0.001) had a significantly higher consumption of UPFs using pesco-vegetarians as reference. There were significant demographic differences across quartiles of UPF consumption among vegetarian subgroups (pesco-vegetarians, vegetarians, and vegans). In a significant multivariable-adjusted association obesity was a predictor of UPF consumption after controlling for duration, age, and sociodemographic characteristics. Obesity vs normal weight was associated with 0.098 greater UPF intake across quartile of UPF intake.		Fair quality
Dos Santos et al., (45)	Brazil	Cross-sectional	925 vegetarians, Female =80.8% and Male =19.2%	The participants are aged 18 years and above from the Brazilian Study on Health, Diet, and Nutrition of Vegetarians	Frequency questionnaire (FFQ). Examined 29 UPF items	The classification of UPF was based on the NOVA classification system	Daily UPF consumption(times/day)	This study examined the association between UPF consumption and overweight among vegetarians. The daily UPF consumption among participants ranged from 0 to 13.1 times per day, with a median of 1.8 times. Age-sex adjusted analysis revealed a significant exposure-response relationship between UPF consumption and overweight, with a prevalence ratio (PR) of 1.09 (95% CI: 1.01-1.17) after adjusting for age (PR 1.03, 95% CI: 1.02-1.04). When comparing consumption quintiles, vegetarians in Q1 (0.00-0.81 times/day) had a 22.7% overweight prevalence, while those in Q5 (3.47-13.12 times/day) showed a 28.1% prevalence.	Good quality

KEY: NOVA refers to the food classification system as defined by Martinez-Steele et al, (28,29) PF: ultra-processed food (includes foods and beverages), BMI: Body Mass Index [weight (kilograms)/height (meters)²], FFQ: Food frequency Questionnaire, WK: Week, %: Percentage, DASH: Dietary Approaches to Stop Hypertension, NAFLD: Non-alcoholic fatty liver disease patients, Kg: Kilogram, NOS: Newcastle Ottawa Scale, CRB: Cochrane Risk of bias. NHANES: National Health and Nutrition Survey