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

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how two different diets affect gut health and metabolism in women with obesity. Participants will follow either a calorie-restricted DASH diet (Dietary Approaches to Stop Hypertension diet) or a calorie-restricted standard American diet for four weeks. Researchers will analyze changes in gut bacteria and their byproducts to gain insights that might help prevent or treat obesity. Women who are non-Hispanic, black or white, generally healthy, and have a BMI of 30 or more may be suitable for this study. As an unphased study, this trial offers participants the chance to contribute to groundbreaking research that could lead to new dietary strategies for managing obesity.

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.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that the DASH diet is generally safe and can help lower cholesterol and blood pressure. This flexible diet supports heart health, and many have followed it without serious side effects.

In this trial, researchers are comparing the DASH diet to a calorie-restricted version of the standard American diet. Both diets are common and well-known, primarily involving changes in the types and amounts of food consumed, making them safe for most people. Participants will likely find these diets easy to follow. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the DASH diet for obesity because it emphasizes a higher intake of carbohydrates and fiber while reducing fat content compared to the standard American diet. This diet not only shifts the macronutrient balance but also significantly increases fiber intake to 34 grams, which can improve digestion and promote satiety, potentially aiding in weight loss. Unlike other dietary approaches that might focus solely on calorie restriction, the DASH diet’s unique composition is designed to support heart health and manage blood pressure, which are additional benefits for individuals struggling with obesity.

What evidence suggests that this trial's treatments could be effective for obesity?

Research has shown that the DASH diet, which participants in this trial may follow, effectively lowers blood pressure and cholesterol. Studies have found it can reduce the systolic blood pressure by about 11.8 mmHg and lower bad cholesterol, such as LDL and VLDL. Additionally, following the DASH diet may help prevent health issues related to being overweight. This trial will compare the DASH diet to a standard American diet, another treatment arm in the study. Over time, the DASH diet also improves heart health compared to a typical American diet. ^{1 3 6 7 8}

Who Is on the Research Team?

Tiffany Carson, PhD

Principal Investigator

Moffitt Cancer Center

Are You a Good Fit for This Trial?

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 for a Trial Participant

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

What Are the Treatments Tested in This Trial?

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.

How Is the Trial Designed?

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+

Published Research Related to This Trial

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]

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]

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 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]

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]

Citations

1. ncbi.nlm.nih.gov ncbi.nlm.nih.gov/books/NBK482514/

DASH Diet To Stop Hypertension - StatPearls - NCBI Bookshelf The diet has been tested in several clinical trials and has been shown to lower cholesterol, saturated fats, and blood pressure.

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10551663/

DASH Diet: A Review of Its Scientifically Proven Hypertension ... During the intervention period, the DASH diet group experienced a significant decrease in systolic blood pressure by 11.8 ± 9.3 mmHg and a ...

3. sciencedirect.com sciencedirect.com/science/article/abs/pii/S093947532500211X

Effect of Dietary Approaches to Stop Hypertension (DASH ... DASH diet significantly reduced total cholesterol, LDL-C and VLDL-C levels. · Greater reductions were observed in ≤8 weeks of interventions. · All of the included ...

4. nature.com nature.com/articles/s41598-019-55285-6

The association of Dietary Approach to Stop Hypertension ... Our findings indicate that adherence to DASH diet may be favourable in prevention of metabolic abnormalities in overweight and obese individuals.

5. ahajournals.org ahajournals.org/doi/10.1161/JAHA.122.026684

Effects of the Dietary Approaches to Stop Hypertension ... In comparison with a typical American diet, the DASH diet reduced high‐sensitivity cardiac troponin I and hs‐CRP progressively over 12 weeks.

6. nhlbi.nih.gov nhlbi.nih.gov/education/dash-eating-plan

DASH Eating Plan | NHLBI, NIH DASH (Dietary Approaches to Stop Hypertension) is a flexible and balanced eating plan that helps create a heart-healthy eating style for life.

7. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/26990451/

The Effect of Dietary Approaches to Stop Hypertension ... Meta-analysis revealed that adults on DASH diet lose more weight (weighted mean difference [WMD] = -1.42 kg, 95% confidence interval [95%CI]: -2.03, -0.82) in 8 ...

8. professional.heart.org professional.heart.org/en/archive/the-dash-diet--is-it-feasible-for-everyone

The DASH Diet Is It Feasible for Everyone Uptake of the DASH diet in observational studies has been associated with lower risk for chronic disease. For example, using data from the National Health and ...