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Completed

NCT Number: NCT02585102

Motivating Value of Vegetables Study

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.

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Key information

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

USDA Grand Forks Human Nutrition Research Center

Grand Forks, North Dakota, 58203, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Recommended Vegetable Intake

Other

Subjects will consume vegetables in amounts recommended by the Dietary Guidelines for Americans

Usual Vegetable Intake

Other

Subjects will consume vegetables in their usual amount

Primary outcomes

  1. Change in relative reinforcing value (RRV) of vegetables as assessed by indicator

    Time frame: 0, 4, 8, 12, 16 weeks

    RRV of vegetables will be assessed by evaluating the number of responses (mouse button presses) a participant is willing to complete to gain access to a vegetable or an alternative snack food.

Secondary outcomes

  1. Change in happiness in response to eating vegetables

    Time frame: 0, 8 weeks

    Happiness will be assessed using a validated questionnaire, the "4-item Subjective Happiness Scale," a 7 point Likert scale with 1=not a very happy person to 7=a very happy person, before and after consuming Dietary Guidelines for Americans (DGA) recommended amounts of vegetables.

Sponsors and collaborators

Lead sponsor

USDA Grand Forks Human Nutrition Research Center

Fed

Collaborators

  • USDA, Western Human Nutrition Research Center
  • University at Buffalo

Registry information

Official study title

Increasing the Relative Reinforcing Values of Vegetables by Incentive Sensitization

Acronym: VegUp

Important dates

Study start
2015
Primary completion
2018
Study completion
2018
First posted
Oct 23, 2015
Registry last updated
Aug 7, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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