The UPGRADE Study will examine how food-processing level and nutritional quality affect energy intake, eating rate, satiety, and glycemic response. In a randomized-order crossover design, each participant will consume three laboratory test meals: low processing/high nutritional quality, high processing/high nutritional quality, and high processing/low nutritional quality. Food intake and eating rate will be measured using a Universal Eating Monitor, alongside satiety, glycemic response, and energy intake during the remainder of the day. The study will also explore whether anxiety and nutrition insecurity influence these responses. Comparisons between participants in Israel and the United States will assess whether background Mediterranean versus Western dietary patterns modify meal responses. The high-processing, low-nutritional-quality meal is expected to result in greater energy intake and eating rate, lower satiety, and a more pronounced glycemic response. Findings will inform future trials and dietary recommendations concerning ultra-processed foods and nutritional quality.
The UPGRADE Study will examine how food-processing level and nutritional quality independently influence eating behavior, energy intake, satiety, and postprandial glycemic response. Using a randomized-order crossover design, each participant will consume three test meals under laboratory conditions: (1) low processing and high nutritional quality; (2) high processing and high nutritional quality; and (3) high processing and low nutritional quality. This design will enable planned comparisons of the effect of processing level when nutritional quality is held constant and the effect of nutritional quality when processing level is held constant. Each meal will be served on a Universal Eating Monitor, which continuously records the amount and rate of food consumption. Additionally, meal time will be recorded during each meal to allow overall meal time calculation. Primary outcomes will include energy intake during the test meal, meal duration, eating rate, postprandial satiety, and glycemic response. Dietary intake during the remainder of the day will also be assessed to determine whether the test meals affect subsequent energy intake. The study will further investigate whether anxiety and nutrition insecurity are associated with eating behavior and whether they modify responses to meals differing in processing level and nutritional quality. Participants with elevated anxiety are hypothesized to consume more energy during the laboratory meals and throughout the remainder of the day. The study will be conducted in Israel, permitting exploratory comparisons between populations exposed to different background dietary patterns. The predominantly Mediterranean-oriented dietary pattern in Israel may influence participants' acute responses to the experimental meals. It is hypothesized that the high-processing, low-nutritional-quality meal will produce the highest energy intake and eating rate, the lowest satiety, the greatest subsequent energy intake, and the most pronounced glycemic response. By distinguishing the effects of food processing from those of nutritional quality, this study will provide preliminary mechanistic evidence to inform future randomized controlled trials and dietary recommendations concerning ultra-processed foods, diet quality, and chronic disease risk.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
40
Interventions: Three distinct meal interventions and six randomized sequence arms. The six arms differ only in intervention order. The meals are: LP-HNQ Meal: Low-processing, high-nutritional-quality test meal consumed under standardized laboratory conditions. HP-HNQ Meal: High-processing, high-nutritional-quality test meal consumed under standardized laboratory conditions. HP-LNQ Meal: High-processing, low-nutritional-quality test meal consumed under standardized laboratory conditions.
Ariel University
Ariel, Israel
RECRUITINGTotal meal duration
Total meal duration, expressed in minutes and seconds, will be determined from the video recording as the elapsed time between placement of the meal tray on the table and the participant indicating that they have finished eating and leaving the table.
Time frame: During each test meal, from placement of the meal tray on the table until the participant indicates that they have finished eating and leaves the table (approximately 5-20 minutes; assessed once per test meal).
Total energy intake in a test meal
At each laboratory visit, participants will receive one of the test meals. Total energy intake (kcal) will be calculated by subtracting the post-meal weight from the pre-meal weight of each food item, multiplying the amount consumed (g) by the item's energy density (kcal/g), and summing the energy consumed across all meal items.
Time frame: During each test meal (approximately 5-20 minutes; assessed once per test meal).
Self-reported level of satiety
Satiety will be assessed using a 10-point numerical visual analogue scale ranging from 1 ("not full at all") to 10 ("extremely full"). Higher scores indicate greater perceived satiety.
Time frame: At each laboratory visit: immediately before the test meal, at meal termination, and 60 minutes after meal termination (assessment period of approximately 60-80 minutes).
Blood glucose level
Blood glucose levels will be measured by capillary fingerstick using a safety lancet, tested with a glucometer (Freestyle Optium Neo (Abbot ©).
Time frame: Measures will be taken at each lab visit at time 0 (prior to consuming the meal) and at times 30, 60 90 and 120 minutes after the meal.
Height
Standing height will be measured without shoes, to the nearest 0.1 cm, using a calibrated wall-mounted stadiometer. Participants will stand upright with their head positioned in the Frankfort horizontal plane. Two measurements will be obtained, and their mean will be used in the analysis. If the two measurements differ by more than 0.5 cm, a third measurement will be obtained.
Time frame: Once at the first laboratory visit (baseline), between 8:00 and 10:00 a.m.; measurement takes approximately 5 minutes.
Weight
Body weight will be measured without shoes and while wearing light clothing, to the nearest 0.1 kg, using the InBody 770 body-composition analyzer. Participants will stand upright and remain still during the measurement.
Time frame: Once at the first laboratory visit (baseline), between 8:00 and 10:00 a.m.; measurement takes approximately 5 minutes.
Anxiety
Anxiety will be measured using the Hebrew Generalized Anxiety Disorder (GAD)-7 scale (Löwe, Decker \& Müller et al, 2008). Participants rate how frequently they experienced each symptom during the preceding two weeks on a scale from 0 ("not at all") to 3 ("nearly every day"). Item scores are summed to produce a total score ranging from 0 to 21, with higher scores indicating greater anxiety symptom severity. Scores of 5, 10, and 15 represent thresholds for mild, moderate, and severe anxiety symptoms, respectively.
Time frame: Once at the first laboratory visit (baseline); the questionnaire assesses symptoms experienced during the preceding two weeks and takes approximately 2-5 minutes to complete.
Household food insecurity risk
Household food insecurity risk will be assessed using the Hunger Vital Sign™, a validated two-item screening tool derived from the U.S. Household Food Security Survey Module. Participants will report whether each statement was "often true," "sometimes true," or "never true" during the preceding 12 months. A positive screen-indicating risk of household food insecurity-will be defined as a response of "often true" or "sometimes true" to either or both items. Participants responding "never true" to both items will be classified as not at risk (Hager et al., 2010).
Time frame: Once at the first laboratory visit (baseline); the questionnaire assesses experiences during the preceding 12 months and takes approximately 2-5 minutes to complete.
Adherence to the Israeli Mediterranean diet pattern
Adherence will be assessed using the 17-item Israel Mediterranean Diet Adherence Screener (I-MEDAS), adapted to reflect the Israeli Mediterranean dietary pattern and national dietary recommendations. Each item is scored 0 or 1 according to whether the specified dietary criterion is met. Scores are summed to produce a total score ranging from 0 to 17, with higher scores indicating greater adherence to the Mediterranean dietary pattern (Abu-Saad et al., 2019).
Time frame: At baseline, before the first test-meal session. The I-MEDAS assesses habitual current dietary intake using item-specific daily or weekly consumption frequencies; it does not employ one uniform retrospective recall period.
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