60 Participants Needed

Reduced-Calorie Diet for Obesity

(Lower CD Trial)

Age: 18+
Sex: Any
Trial Phase: Academic
Sponsor: The University of Tennessee, Knoxville
No Placebo GroupAll trial participants will receive the active study treatment (no placebo)

Trial Summary

Will I have to stop taking my current medications?

The trial does not specify whether you need to stop taking your current medications. However, if you are taking weight loss medication, you cannot participate in the trial.

What data supports the effectiveness of a reduced-calorie diet treatment for obesity?

Research shows that lower-calorie diets can lead to significant short-term weight loss, and when combined with other treatments like medication, they can help maintain weight loss over a longer period.12345

Is a reduced-calorie diet safe for treating obesity?

Very low-calorie diets (VLCDs) have been used for about ten years and are generally safe when patients are properly selected, given high-quality protein supplements, and monitored by healthcare professionals. However, there have been concerns about safety, especially when liquid protein diets were sold over the counter, which were linked to deaths. Proper monitoring and support are crucial to ensure safety.678910

How does the reduced-calorie diet treatment for obesity differ from other treatments?

The reduced-calorie diet treatment for obesity is unique because it focuses on significant caloric restriction, often under medical supervision, which can lead to rapid weight loss. Unlike other treatments, it emphasizes a very-low-calorie diet (400 to 800 kcal/d) combined with behavior modification to help maintain weight loss over time.1112131415

What is the purpose of this trial?

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.

Eligibility Criteria

This trial is for adults aged 18-65 with a BMI of 27-45 kg/m2 who are not currently in a weight loss program or taking weight loss meds, haven't lost more than 5% body weight recently, don't have major heart conditions or psychiatric diseases, aren't pregnant or post-partum within six months, and can walk two blocks without stopping.

Inclusion Criteria

Body mass index (BMI) between 27 and 45 kg/m2

Exclusion Criteria

Report a heart condition, chest pain during periods of activity or rest, or loss of consciousness on the Physical Activity Readiness Questionnaire (PAR-Q)
I am in a weight loss program or taking medication for it, or I've lost more than 5% of my body weight in the last 6 months.
I have a significant psychiatric condition or brain disorder.
See 4 more

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants follow a diet low in dietary energy density for weight loss

12 weeks
Weekly check-ins (virtual or in-person)

Follow-up

Participants are monitored for changes in weight, dietary intake, and physical activity

4 weeks

Treatment Details

Interventions

  • Common components of intervention
Trial Overview The study tests whether eating foods low in energy density (calories relative to food weight) helps with weight loss. It explores if it's better to increase low-energy-dense foods like fruits and vegetables or decrease high-energy-dense foods like fats.
Participant Groups
2Treatment groups
Active Control
Group I: COMBINATIONActive Control1 Intervention
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 II: INCREASEActive Control1 Intervention
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.

Find a Clinic Near You

Who Is Running the Clinical Trial?

The University of Tennessee, Knoxville

Lead Sponsor

Trials
93
Recruited
19,500+

Findings from Research

In a study involving 53 overweight patients, those following a healthy eating diet lost an average of 6.0 kg over 12 weeks, which was significantly more than the 4.2 kg lost by those on an energy prescription diet.
Both dietary approaches resulted in clinically significant weight loss, but the healthy eating diet proved to be more effective, suggesting the need for further research to confirm these findings.
Controlled clinical trial of two weight reducing diets in a NHS hospital dietetic outpatient clinic: a pilot study.Taylor, F., Irons, L., Finn, P., et al.[2007]
In a study involving 53 overweight patients, those following a healthy eating diet lost an average of 6.0 kg over 12 weeks, which was significantly more than the 4.2 kg lost by those on an energy prescription diet.
Both dietary approaches resulted in clinically significant weight loss, but the healthy eating diet proved to be more effective, suggesting the need for further research to confirm these findings.
Controlled clinical trial of two weight reducing diets in a NHS hospital dietetic outpatient clinic - a pilot study.Taylor, FC., Irons, LJ., Finn, P., et al.[2019]
Lower-calorie diets consistently lead to greater short-term weight loss (less than 6 months) compared to higher-calorie diets, but this advantage tends to diminish over the long term (beyond 12 months).
While different macronutrient compositions (like low-carb vs. low-fat) may show short-term benefits, there are few significant long-term differences in weight loss, highlighting the importance of dietary adherence for sustained results.
Dietary interventions for obesity: clinical and mechanistic findings.Chao, AM., Quigley, KM., Wadden, TA.[2022]

References

Review of 3-year outcomes of a very-low-energy diet-based outpatient obesity treatment programme. [2016]
Controlled clinical trial of two weight reducing diets in a NHS hospital dietetic outpatient clinic: a pilot study. [2007]
Controlled clinical trial of two weight reducing diets in a NHS hospital dietetic outpatient clinic - a pilot study. [2019]
Dietary interventions for obesity: clinical and mechanistic findings. [2022]
What interventions should we add to weight reducing diets in adults with obesity? A systematic review of randomized controlled trials of adding drug therapy, exercise, behaviour therapy or combinations of these interventions. [2018]
[Effectiveness and safety of Very Low Calory Diets in obese patients]. [2018]
Descriptive analysis of reported adverse events associated with anti-obesity medications using FDA Adverse Event Reporting System (FAERS) databases 2013-2020. [2022]
Post-marketing withdrawal of anti-obesity medicinal products because of adverse drug reactions: a systematic review. [2022]
Very low calorie diets--history, safety and recent developments. [2009]
Serious adverse events reported for antiobesity medicines: postmarketing experiences from the EU adverse event reporting system EudraVigilance. [2018]
[Long-term weight reduction. Current therapy approaches in obesity]. [2015]
Nutritional and behavioral modification therapies of obesity: facts and fiction. [2018]
13.United Statespubmed.ncbi.nlm.nih.gov
Medical management of obesity. [2005]
14.United Statespubmed.ncbi.nlm.nih.gov
Treatment of obesity by moderate and severe caloric restriction. Results of clinical research trials. [2019]
15.United Statespubmed.ncbi.nlm.nih.gov
Obesity. Part II--Treatment. [2018]
Unbiased ResultsWe believe in providing patients with all the options.
Your Data Stays Your DataWe only share your information with the clinical trials you're trying to access.
Verified Trials OnlyAll of our trials are run by licensed doctors, researchers, and healthcare companies.
Back to top
Terms of Service·Privacy Policy·Cookies·Security