Lowering Caloric Density of the Diet

NCT ID: NCT02674971

Last Updated: 2025-04-03

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2015-12-31
• Study Completion Date: 2025-12-31

Brief Summary

For weight loss to occur, energy intake needs to be reduced to incur an energy deficit. One dietary strategy that may facilitate reducing energy intake and enhancing weight loss is consuming a diet low in dietary energy density (ED). The ED of a given food, defined as the ratio of energy of the food to the weight of the food (kcal/g), is largely determined by water content, but is also affected by fat and fiber. Although the 2010 Dietary Guidelines encourage an eating pattern low in energy density (ED) to manage weight, it is currently not known what the best strategy is for reducing ED in the diet. Eating a greater number of foods low in ED or reducing the number of foods high in ED may reduce overall dietary ED. As ED is believed to reduce intake by allowing a greater weight of food relative to total energy consumed assisting with enhancing feelings of fullness, it is anticipated that either increasing consumption of low-ED foods in the diet alone or combining an increase in consumption of low-ED foods with a decrease in consumption of high-ED foods may be the best strategies for reducing overall dietary ED for weight loss.

Conditions

Obesity; Feeding Behavior

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

INCREASE

This condition will be instructed to make food consumption decisions based solely upon the ED of a food. The goal of the ED condition will be to consume at least 10 foods ≤ 1.0 kcal/g (i.e., fruits and vegetables, broth based soups, non-fat yogurts, some legumes, egg substitutes, some white fish, etc.) per day.

Group Type: ACTIVE_COMPARATOR

Common components of intervention

Intervention Type: BEHAVIORAL

12-week standard lifestyle intervention for obesity, which consists of weekly meetings. Each meeting will last 60 minutes, with participants attending group meetings specific for their condition. In all meetings, participants will be weighed, homework assignments will be verbally reviewed, and a behavioral lesson will be presented. Basic behavioral lessons, will be similar to those that have been successfully used in the Diabetes Prevention Program (DPP) and Look AHEAD. Topics to be covered in the meetings will focus on the dietary prescriptions and dietary information for each condition, the physical activity goal, energy balance, and behavioral strategies. Each session will conclude with reminding participants of their dietary and physical activity goals, and having participants self-monitor these behaviors every day and implement the behavioral strategies discussed in the session.

COMBINATION

This condition will be identical to the INCREASE condition, except it will also have a goal regarding the number of high-ED foods to consume and substituting low-ED foods for high-ED foods. Thus, this condition will have ED goals to consume at least 10 foods ≤ 1.0 kcal/g (i.e., fruits and vegetables, broth based soups, non-fat yogurts, some legumes, egg substitutes, some white fish, etc.) and no more than 2 foods ≥ 3.0 kcal/g (i.e., crackers, chips, cookies, hard cheeses, hot dogs, salad dressings, etc.) per day. Foods with an ED \>1.0 kcal/g but \< 3.0 kcal/g will be unlimited; however, lower ED foods will be strongly encouraged. Furthermore, additions to beverages (i.e., sugar, cream) will count toward the \> 3.0 kcal/g goal if the additions meet that ED criteria.

Group Type: ACTIVE_COMPARATOR

Common components of intervention

Intervention Type: BEHAVIORAL

12-week standard lifestyle intervention for obesity, which consists of weekly meetings. Each meeting will last 60 minutes, with participants attending group meetings specific for their condition. In all meetings, participants will be weighed, homework assignments will be verbally reviewed, and a behavioral lesson will be presented. Basic behavioral lessons, will be similar to those that have been successfully used in the Diabetes Prevention Program (DPP) and Look AHEAD. Topics to be covered in the meetings will focus on the dietary prescriptions and dietary information for each condition, the physical activity goal, energy balance, and behavioral strategies. Each session will conclude with reminding participants of their dietary and physical activity goals, and having participants self-monitor these behaviors every day and implement the behavioral strategies discussed in the session.

Interventions

Common components of intervention

12-week standard lifestyle intervention for obesity, which consists of weekly meetings. Each meeting will last 60 minutes, with participants attending group meetings specific for their condition. In all meetings, participants will be weighed, homework assignments will be verbally reviewed, and a behavioral lesson will be presented. Basic behavioral lessons, will be similar to those that have been successfully used in the Diabetes Prevention Program (DPP) and Look AHEAD. Topics to be covered in the meetings will focus on the dietary prescriptions and dietary information for each condition, the physical activity goal, energy balance, and behavioral strategies. Each session will conclude with reminding participants of their dietary and physical activity goals, and having participants self-monitor these behaviors every day and implement the behavioral strategies discussed in the session.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• 1) age between 18 and 65 years and 2) a body mass index (BMI)7 between 27 and 45 kg/m2.

Exclusion Criteria

1. report a heart condition, chest pain during periods of activity or rest, or loss of consciousness on the Physical Activity Readiness Questionnaire (PAR-Q)8 (medical conditions that could limit exercise for safety reasons will be required to obtain written physician consent before participating in the investigation)

2. report being unable to walk for 2 blocks (1/4 mile) without stopping

3. are currently participating in a weight loss program and/or taking weight loss medication or lost > 5% of body weight during the past 6 months

4. report major psychiatric diseases or organic brain syndromes

5. have had bariatric surgery or are planning to have bariatric surgery within the next 4 months

6. intend to move outside of the metropolitan area within the time frame of the investigation

7. are pregnant, lactating, < 6 months post-partum, or plan to become pregnant during the investigation.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

The University of Tennessee, Knoxville

OTHER

Sponsor Role: lead

Responsible Party

Hollie Raynor

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Healthy Eating and Activity Laboratory, University of Tennessee

Knoxville, Tennessee, United States

Countries

United States

Other Identifiers

UTKIRB-15-02609

Identifier Type: -

Identifier Source: org_study_id