Table 3:

Studies providing baseline, unadjusted or indirect evidence of association between UPF 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
Hall et al., (42)	United States	Randomized controlled trial	20 Volunteers Male = 11 Female = 9	Participants were admitted as inpatients to the Metabolic Clinical Research Unit at the NIH Clinical Center where they resided in individual rooms. Age 18–50 years; weight stable (<±5% over past 6 months); body mass index ≥20 kg/m2; body weight ≥53 kg; no signs of arrhythmia and without diabetes.	Weighing remaining food and beverages from each meal. The nutrient and energy intake were calculated using nutrition software.	The study compared a Low-fat (plant-based) diet formulated with low UPF (26%) and a low-carbohydrate (anima-based) diet with low UPF (32%) per the NOVA classification system.	% energy from UPFs.	The study compared a Low-fat (plant-based) diet formulated with low UPF (26%) and a low-carbohydrate (animal-based) diet with low UPF (32%). Two-week weight loss outcomes were comparable between the 2 diet groups. The plant-based low-fat diet resulted in a total weight loss of 1.09 ± 0.32 kg (p = 0.003), which was not significantly different (p =0.15) from the weight loss observed with the low-carbohydrate diet (1.77 ± 0.32 kg, p =0.0001) There were no differences in weight loss outcomes between low-carbohydrate and low-fat diet arms when UPF intake was between 26-32% of kcal.	Poor quality
Tu et al., (40)	United Kingdom	Prospective cohort	121 300 participants Female 56.4%	UK Biobank participants. Age 40 to 69 years with adherence to dietary patterns (Mediterranean-stye, DASH, or plant-based diet)	24-hour dietary recall questionnaires of 238 common food and beverage items. As a means of two or more 24-hour dietary recalls.	The classification of ultra-processed foods was based on the NOVA classification system. NOVA group 4 represents food and beverages.	UPF intake (% by food weight).	The median UPF intake (% by food weight) of total food mass was 11.5. Across quintiles of Mediterranean diet score at baseline, participants with higher vs. lower (Q5 vs. Q1) adherence to the Mediterranean diet consumed lower UPFs (9.8% vs. 11.5% by weight, p<0.001) and had lower BMI (25.8 vs. 27.5, p < 0.001). Similarly, across quintiles of DASH diet score (Q5 vs. Q1), participants with higher vs. lower adherence consumed lower UPFs (8.4 vs. 11.5 kcal, p<0.001) and had lower BMI (25.1 vs. 26.7, p < 0.001). Across quintiles of UPF intake, participants in Q5 vs. Q1 consumed higher UPF (25.1 vs. 11.5, p < 0.001) and had higher BMI (27.8 vs. 26.7, p < 0.001)	Poor quality
Orlich et al., (39)	North America	Prospective Cohort	77437 men and women participants	AHS-2 cohort recruited from Seventh-day Adventist churches in the United States and Canada. Non-vegetarians and vegetarians (comprising vegans, lacto-ovo vegetarians, pesco vegetarians, and semi vegetarians)	FFQ: dietary intake was assessed at baseline by a previously validated self-administered quantitative FFQ of >200 food items	The classification of ultra-processed foods was based on the NOVA classification system	% of energy from UPFs.	UPF contributed 27.4% median of total dietary intake. Participants across UPF intake quintiles (Q1 vs. Q5), had a higher BMI (25.24 vs. 28.91, p < 0.001). All analyses unadjusted for confounding factors	Poor quality
Garcia et al.,(49)	Spain	Prospective Cohort	70 participants	FLIPAN participants following the Mediterranean diet, aged 40 and 60	validated 143-item semi-quantitative FFQ	The classification of ultra-processed foods was based on the NOVA classification system	%UPF intake (g/day)	Participants were divided into three groups (T1-T3) based on changes in UPF consumption over 6 months. Mediterranean diet adherence was inversely correlated with UPF intake. There were no significant differences in BMI by tertiles of reduction of UPF intake across all groups (T1: −1.4 kg/m2; T2/T3: −1.1 kg/m2, p= 0.697)	Por Quality
Monserrat-Mesquida et al., (43)	Spain	Cross-sectional	100 Non-alcoholic fatty liver disease patients. Men = 56% and women =43.5%	NAFLD patients from the Balearic Islands, with mean age of 51.8 years	Semiquantitative FFQ: Dietary intakes were obtained using a validated 148-item FFQ	The classification of ultra-processed foods was based on the NOVA classification system	% UPF Intake (g/day)	Participants were classified into tertiles based on their adherence to the Mediterranean diet. Individuals with low vs. high adherence to the Med diet had higher % UPF consumption. (33.3 vs. 12.7, p<0.001). However, no association was observed between UPF consumption and BMI, with mean BMI values of 32.7, 32.5, and 33.4 for low, moderate, and high adherence groups, respectively	Poor quality
Leitao et al., (44)	Brazil	Cross-sectional	774 participants Male= 17.7% Female = 82.3%	The participants were 24-35 years old from the Vegan Eating Habits Evaluation Survey with self-reported adherence to a vegan diet.	24-hour dietary recalls.	The classification of ultra-processed foods was based on the NOVA classification system	% of energy from UPFs.	UPF intake was 13.2% of food intake in the vegan population. In both men and women there was no association between UPF and mean BMI	Poor quality
Sullivan et al., (24)	United States	Cross-sectional	51,698 participants	The participants aged 20 years and above from NHANES data who consumed plant-based food.	Completion of at least one 24-hour dietary recall	The classification of ultra-processed foods was based on the NOVA classification system	% of energy from UPFs	Plant-based consumers were defined as individuals obtaining ≥50% of their total protein from plant sources.There was no association between UPF consumption and weight-related outcomes in plant-based consumers. Over 2 decades, UPF intake remained stable among plant-based consumers, consistently comprising over half of their total energy intake (50.7–57% kcal; p =0.34) while UPF consumption among non-PB consumers significantly increased from 51 to 55.4 (p <0.001). The proportion of individuals with normal and overweight increased, while obesity rates remained stable among PB consumers.	Poor quality
Chang et al., (46)	United Kingdom	Cross-sectional	45,057 flexitarians, 4932 pescatarians, 4119 vegetarians and 159 vegans	UK Biobank participants’ mean age 58.2	24-h recalls	The classification of ultra-processed foods was based on the NOVA classification system	% of energy from UPFs	The study found that UPF consumption varied across dietary groups, but no clear linear trend linked higher UPF intake to higher BMI classifications. Vegans, who consumed 50.3% of their energy from UPF, had the lowest rates of obesity (6.2%) and overweight (31.4%) compared to vegetarians who consumed 51.7% of UPF and were 31.8% overweight and 12.3% obese (p<0.001)	Poor quality

KEY: NOVA refers to the food classification system as defined by Martinez-Steele et al, (28,29) UPF: 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