DASH Diet for Obesity

Overseen By Tiffany Carson, PhD

Age: 18+

Sex: Female

Trial Phase: Academic

Sponsor: H. Lee Moffitt Cancer Center and Research Institute

Must not be taking: Antibiotics, Probiotics

Disqualifiers: GI conditions, Tobacco, Alcohol, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 4 weeks

28 Participants Needed

Trial Summary

What is the purpose of this trial?

The investigators will conduct a 2-arm randomized controlled pilot, feasibility feeding study in which 28 participants will be randomized to receive either a calorie-restricted Dietary Approaches to Stop Hypertension (DASH) diet or a calorie-restricted standard American diet provided by the study for 4 weeks. Participants will be non-Hispanic black or white, generally healthy females (14 black, 14 white). The investigators will collect fecal samples at multiple time points before, during, and after the dietary intervention to analyze for changes in the gut microbiota and functional-level metabolic products. This work will be led by an interdisciplinary team including expertise in bio-behavioral science, microbiology, nutrition science, bioinformatics, and biostatistics all with cross-cutting expertise in health disparities, prevention research, nutrition, the gut microbiota, inflammation and other biomarkers. The rationale for the proposed research is that once the interactions between race, diet, and the gut microbiota are more fully understood, targeted diet modifications may provide new and innovative approaches for the prevention and treatment of obesity and obesity-related diseases.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications. However, it does exclude participants with major medical conditions and recent antibiotic or probiotic use, which might suggest some restrictions.

What data supports the effectiveness of the DASH diet treatment for obesity?

Research shows that the DASH diet, which includes lots of fruits, vegetables, and low-fat foods, can help with weight loss and improve conditions like diabetes and heart health. This suggests it might also be effective for managing obesity. ^{1 2 3 4 5}

Is the DASH diet safe for humans?

The DASH diet is generally safe for most people and can be used alongside medications and other lifestyle changes. However, people with chronic kidney or liver disease, heart failure, uncontrolled diabetes, lactose intolerance, or celiac disease should consult a doctor before starting, as they may need to adjust the diet. ^{1 3 6 7 8}

How does the DASH diet treatment for obesity differ from other treatments?

The DASH diet is unique because it emphasizes a balanced intake of fruits, vegetables, whole grains, and low-fat dairy, while limiting saturated fats and sugars, which can help with weight management and improve heart health. Unlike other diets, it is specifically designed to lower blood pressure and is recommended for managing diabetes and potentially reducing cancer risk. ^{1 2 5 9 10}

Research Team

Tiffany Carson, PhD

Principal Investigator

Moffitt Cancer Center

Eligibility Criteria

This trial is for non-Hispanic black or white women, aged 19-65 with obesity (BMI >= 30 kg/m^2). Participants must be able to visit the Bionutrition Unit daily. Those who have used antibiotics or probiotics recently, smoke, drink heavily, or have certain GI conditions and major diseases like diabetes cannot join.

Inclusion Criteria

I am between 19 and 65 years old.

I can visit the Bionutrition Unit every day.

I am female.

Exclusion Criteria

You currently drink a lot of alcohol.

I have not taken antibiotics or probiotics in the last 90 days.

You smoke or use tobacco products.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either a calorie-restricted DASH diet or a calorie-restricted standard American diet for 4 weeks

4 weeks

Multiple visits for fecal sample collection

Follow-up

Participants are monitored for changes in inflammatory markers, short chain fatty acids, secondary bile acids, and weight

2 weeks

Treatment Details

Interventions

• DASH diet
• standard American diet

Trial Overview The study compares two diets over four weeks: a calorie-restricted DASH diet versus a standard American diet. It aims to see how these diets affect gut bacteria and metabolism in participants. The results could lead to new dietary strategies for preventing obesity-related health issues.

Participant Groups

Group I: DASH diet Experimental Treatment 1 Intervention

calorie-restricted DASH diet (25% fat; 57% carbohydrate; 18% protein; 34 g fiber

Group II: standard American diet Active Control 1 Intervention

calorie-restricted standard American diet (35% fat; 51% carbohydrate; %15 protein; 14 g fiber

Who Is Running the Clinical Trial?

H. Lee Moffitt Cancer Center and Research Institute

Lead Sponsor

Trials

576

Recruited

145,000+

Findings from Research

The DASH eating plan is beneficial for people with diabetes, as it not only helps control blood pressure but also improves insulin resistance and reduces high cholesterol levels.

This diet encourages a variety of healthy foods, making it suitable for the whole family and effective in managing weight and obesity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

DASH Eating Plan: An Eating Pattern for Diabetes Management. Campbell, AP.[2020]

The OmniHeart study is a randomized crossover trial involving 160 adults with prehypertension or Stage 1 hypertension, designed to compare the effects of a carbohydrate-rich diet with diets high in protein or unsaturated fat on blood pressure and cholesterol levels.

The study aims to provide insights into how different macronutrient compositions can influence cardiovascular risk factors, potentially guiding dietary recommendations for better heart health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Rationale and design of the Optimal Macro-Nutrient Intake Heart Trial to Prevent Heart Disease (OMNI-Heart). Carey, VJ., Bishop, L., Charleston, J., et al.[2017]

The DASH dietary pattern is linked to a significant reduction in the incidence of cardiovascular disease (CVD) by 20%, coronary heart disease by 21%, stroke by 19%, and diabetes by 18%, based on a review of 15 studies involving over 942,000 participants.

In controlled trials, the DASH diet led to notable improvements in blood pressure, with a decrease in systolic blood pressure by 5.2 mmHg and diastolic blood pressure by 2.6 mmHg, along with reductions in total cholesterol, LDL cholesterol, HbA1c, fasting insulin, and body weight.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

DASH Dietary Pattern and Cardiometabolic Outcomes: An Umbrella Review of Systematic Reviews and Meta-Analyses. Chiavaroli, L., Viguiliouk, E., Nishi, SK., et al.[2020]

The DASH diet, which emphasizes fruits, vegetables, and low-fat dairy, has been shown to effectively lower blood pressure in individuals with prehypertension and stage I hypertension, based on findings from the DASH trial.

While the DASH diet is generally safe for most patients, caution is advised for those with chronic kidney or liver diseases, and modifications may be needed for individuals with chronic heart failure, uncontrolled diabetes, lactose intolerance, or celiac disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Dietary Approaches to Stop Hypertension (DASH) eating pattern in special populations. Tyson, CC., Nwankwo, C., Lin, PH., et al.[2021]

In a study of 20,993 women aged 55 to 69, a greater adherence to the DASH diet was linked to a lower incidence of self-reported hypertension, suggesting a potential protective effect against developing high blood pressure.

However, after adjusting for other risk factors, the study found little evidence that adherence to the DASH diet independently influenced long-term mortality from cardiovascular diseases, indicating that achieving very high concordance with the diet may be necessary for significant health benefits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Degree of concordance with DASH diet guidelines and incidence of hypertension and fatal cardiovascular disease. Folsom, AR., Parker, ED., Harnack, LJ.[2018]

The DASH diet, which emphasizes fruits, vegetables, nuts, and low-fat dairy while reducing saturated fats, led to an average reduction of 6 mmHg in systolic and 3 mmHg in diastolic blood pressure among patients, with even greater reductions in those with high blood pressure.

These significant blood pressure reductions were observed within just 2 weeks of starting the diet, indicating its potential effectiveness for managing hypertension in a primary care setting.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary Approaches to Stop Hypertension (DASH) in clinical practice: a primary care experience. Kolasa, KM.[2020]

Following the DASH diet, which is rich in fiber, nutrients, and antioxidants, is linked to a lower prevalence of various cancers, suggesting it may have protective effects against cancer development.

While this review indicates a positive association between the DASH diet and cancer prevention, further longitudinal studies are needed to clarify the exact relationship due to the complex interactions among different foods and nutrients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary approach to stop hypertension (DASH): diet components may be related to lower prevalence of different kinds of cancer: A review on the related documents. Onvani, S., Haghighatdoost, F., Azadbakht, L.[2020]

References

1. England pubmed.ncbi.nlm.nih.gov

The effect of dietary approaches to stop hypertension (DASH) diet on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials. [2022]

2. United States pubmed.ncbi.nlm.nih.gov

DASH Eating Plan: An Eating Pattern for Diabetes Management. [2020]

3. England pubmed.ncbi.nlm.nih.gov

Rationale and design of the Optimal Macro-Nutrient Intake Heart Trial to Prevent Heart Disease (OMNI-Heart). [2017]

4. United States pubmed.ncbi.nlm.nih.gov

Influence of the DASH diet and other low-fat, high-carbohydrate diets on blood pressure. [2019]

5. Switzerland pubmed.ncbi.nlm.nih.gov

DASH Dietary Pattern and Cardiometabolic Outcomes: An Umbrella Review of Systematic Reviews and Meta-Analyses. [2020]

6. United States pubmed.ncbi.nlm.nih.gov

The Dietary Approaches to Stop Hypertension (DASH) eating pattern in special populations. [2021]

7. United States pubmed.ncbi.nlm.nih.gov

The effect of dietary patterns on estimated coronary heart disease risk: results from the Dietary Approaches to Stop Hypertension (DASH) trial. [2021]

8. United States pubmed.ncbi.nlm.nih.gov

Degree of concordance with DASH diet guidelines and incidence of hypertension and fatal cardiovascular disease. [2018]

9. United States pubmed.ncbi.nlm.nih.gov

Dietary Approaches to Stop Hypertension (DASH) in clinical practice: a primary care experience. [2020]

10. India pubmed.ncbi.nlm.nih.gov

Dietary approach to stop hypertension (DASH): diet components may be related to lower prevalence of different kinds of cancer: A review on the related documents. [2020]