Clinical trial NCT02585102: Motivating Value of Vegetables Study
Official title: Increasing the Relative Reinforcing Values of Vegetables by Incentive Sensitization
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Overweight
Obesity
Keywords: Vegetables
Lead sponsor: USDA Grand Forks Human Nutrition Research Center
Sponsor class: FED
Collaborators: name: USDA, Western Human Nutrition Research Center
name: University at Buffalo
First posted: 2015-10-23
Enrollment: 102
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

Brief summary: The purpose of this study is to see if perceived barriers to vegetable consumption can be overcome by making it easier for people eat more vegetables and to see if the effects last over time.

Detailed description: High vegetable consumption is associated with maintenance of a healthy body weight. Americans do not eat vegetables in the amounts recommended by the dietary guidelines and interventions to increase intake have had limited results. Reported barriers to consumption include not knowing how to prepare them and being unused to eating them.To get people to eat vegetables, they have to be motivated to do so. Repeated consumption of snack foods increases overweight and obese individuals' motivation to eat snack foods. The investigators hypothesize that by increasing people's consumption of vegetables by making them easy to eat will increase the motivation value of vegetables. For this study the investigators propose to provide minimally-processed (cleaned, packaged) vegetables to overweight and obese individuals. The motivating value of vegetables will be measured using a computer task where people play a game to earn points towards portions of a vegetable or a neutral food (crackers). The investigators will determine potential moderators of the increase in the motivating value of vegetables such as genetics (single nucleotide polymorphisms) that are associated with the motivating value of food and whether people substitute eating vegetables for other foods. The investigators will also determine changes in adiposity as a result of vegetable consumption. Lastly, the investigators will determine if repeated consumption increases psychosocial predictors of vegetable intake, such as self-efficacy of eating vegetables.

Eligibility criteria: Inclusion Criteria:

* BMI ≥ 25 kg/m2
* Currently eating ≤ 1 cup of vegetables (apart from fried potatoes) per day
* Willing to consent to study conditions

Exclusion Criteria:

* BMI \< 25 kg/m2
* Age \< 18 years or \> 65 years
* Currently dieting or following specific diet
* Allergies or unwillingness to consume study foods
* Gastrointestinal disorder or disease
* Pregnant, lactating, or planning pregnancy
* Current smoker or tobacco user
* High dietary restraint or certain eating patterns
* Inability to give consent
* Medications that would influence appetite, weight gain, or weight loss
* Exclusionary medications: Didrex, Tenuate, Belviq, Contrave, Phendimetrazine, Adipex-P, Suprenza, Xenical, Qsymia, Saxenda

Primary outcomes:
measure: Change in relative reinforcing value (RRV) of vegetables as assessed by indicator
timeFrame: 0, 4, 8, 12, 16 weeks
Secondary outcomes:
measure: Change in happiness in response to eating vegetables
timeFrame: 0, 8 weeks
Other outcomes:
Locations:
city: Grand Forks
country: United States
facility: USDA Grand Forks Human Nutrition Research Center
state: North Dakota
Study officials:
affiliation: USDA Grand Forks Human Nutrition Research Center
name: James N Roemmich, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Casperson SL, Jahns L, Duke SE, Nelson AM, Appleton KM, Larson KJ, Roemmich JN. Incorporating the Dietary Guidelines for Americans Vegetable Recommendations into the Diet Alters Dietary Intake Patterns of Other Foods and Improves Diet Quality in Adults with Overweight and Obesity. J Acad Nutr Diet. 2022 Jul;122(7):1345-1354.e1. doi: 10.1016/j.jand.2022.03.008. Epub 2022 Mar 9.
citation: Cao JJ, Roemmich JN, Sheng X, Jahns L. Increasing Vegetable Intake Decreases Urinary Acidity and Bone Resorption Marker in Overweight and Obese Adults: An 8-Week Randomized Controlled Trial. J Nutr. 2021 Nov 2;151(11):3413-3420. doi: 10.1093/jn/nxab255.
citation: Casperson SL, Jahns L, Temple JL, Appleton KM, Duke SE, Roemmich JN. Consumption of a Variety of Vegetables to Meet Dietary Guidelines for Americans' Recommendations Does Not Induce Sensitization of Vegetable Reinforcement Among Adults with Overweight and Obesity: A Randomized Controlled Trial. J Nutr. 2021 Jun 1;151(6):1665-1672. doi: 10.1093/jn/nxab049.