Ultra-Processing and Nutritional Quality: Glycemic Response, Appetite, Dietary Energy Intake, and Eating Rate

Interactions Between Food Processing Level, Nutrition Quality, Nutrition Security and Anxiety in Israeli Adults: Influence on Dietary Intake

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.

Inclusion Criteria:

• body mass index (BMI) 20-40 kg/m2

Exclusion Criteria:

• pregnant nor lactating
• people with food allergies of food intolerance