Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03639350 |
| Other study ID # |
12619302B |
| Secondary ID |
4502286 |
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
September 12, 2016 |
| Est. completion date |
June 15, 2018 |
Study information
| Verified date |
August 2018 |
| Source |
University of Hawaii |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
This pilot study aims to develop a study design to test the difference between a fasting diet
and a heart healthy diet, assess participants' adherence to the study design, and to test
whether either diet helps to reduce fat wrapped around the organs in the stomach area and
total body fat in East Asian American adults. 70 men and women residents of Oahu Hawai'i,
aged 35-55, who are overweight or obese and have moderate to high amounts of fat around
organs in the stomach area, of Japanese, Chinese, or Korean ancestry, will be equally
distributed to either the fasting diet or the heart healthy diet and asked to follow this
diet for the 12-week study. Each diet has set requirements for energy, protein,
carbohydrates, and fat. The fasting diet has two days of fasting, where participants will be
asked to follow a low carbohydrate- low energy diet, and five days of a balanced diet without
any energy restriction (the Mediterranean diet). The other group will follow a heart healthy
diet (Dietary Approaches to Stop Hypertension diet) for all seven days without any energy
restriction. Both groups will be asked to follow a moderate exercise program (one hour of
walking five days a week). Dietitians will provide information on diet and exercise
requirements to the participants at the start of the study. Dietitians will contact the
participants seven times, primarily by phone, to offer support and to check if the
participants are following prescribed diet and exercise plans. Participants will use a mobile
phone app to take images of all foods and drinks for four days at the beginning, middle and
end of the 12-week study. Body measurements, including measurements of body fat, will be
taken at the beginning and end of the study by trained clinic staff. The analysis of the food
images, participants' self-reported compliance to diet and exercise plans, and body
measurements will be used to determine if the study design and participant compliance to the
study are successful, and to assess which diet is better at reducing total body fat and fat
around the organs in the stomach region.
Description:
Background and rationale: East Asian adults are known to have higher levels of visceral
adiposity than whites, African Americans, and Hispanic adults in the US. This visceral fat
deposition, because of its close proximity to the portal vein, has greater metabolic activity
and is associated with a greater risk of cardiometabolic diseases and possibly certain
cancers (e.g., breast and colorectal cancers). Newly introduced weight loss interventions,
specifically, intermittent energy restriction (IER), have been proposed to be as effective as
continuous energy restriction, achieve higher and long-term compliance, and may predominantly
result in a decrease in visceral fat. Thus, implementing this novel weight loss intervention
among East Asian Americans with high visceral fat deposition would be particularly beneficial
.
Goal: This study aims to demonstrate the feasibility to conduct an intermittent energy
restriction (IER) nutritional intervention aimed at reducing visceral adiposity in overweight
Asian Americans middle-aged adults.
1. To finalize and implement a protocol for an IER intervention plus exercise with the goal
of reducing visceral fat in overweight adult East Asian Americans (EAA). The protocol
will include an intensive dietary intervention and an exercise program administered by a
dietitian through individual meetings and the use of new technologies to monitor dietary
compliance.
2. After eligibility screening, 70 individuals will be randomized to either the intensive
intervention diet group or to a non-intensive intervention (active comparator) diet
group for 12 weeks. The intensive intervention group will follow a low carbohydrate- low
energy IER diet for two consecutive days, and the Mediterranean (MED) diet for the other
five days and meet estimated energy requirements (IER + MED group). The active
comparator group will follow the Dietary Approaches to Stop Hypertension (DASH) diet for
all seven days and meet estimated energy requirements (DASH group). With an expected
attrition rate of ~25%, the investigators expect ~50 participants to complete the study.
3. To evaluate study retention, protocol adherence, effect size of the intervention on body
weight, total adiposity, DXA measured visceral fat (main outcome), estimated visceral
adipose tissue area, and selected clinical measures (e.g., waist circumference, hip
circumference).
Design: Randomized lifestyle intervention trial to compare the effects of two twelve-week
diets - (i) an IER + MED diet versus (ii) DASH diet- on DXA quantified visceral fat
deposition distribution in overweight/obese men and women. Both intervention groups will be
asked to follow a moderate exercise program (1 hour of walking five days a week). The
research will be carried out in the University of Hawaii Cancer Center (UHCC). The
investigators will determine and compare the primary and secondary endpoints at least five
days after the last 2 energy-restricted days to a corresponding day of the week in the DASH
group at the completion of the 12th week of IER+MED or DASH diets.
Assessing dietary intervention adherence: Dietary intake of energy, fat (monounsaturated
fatty acids (MUFA), Polyunsaturated fatty acids (PUFA) and saturated fat), carbohydrate,
protein, dietary fiber and alcohol will be assessed prior to the first week of intervention,
the 5-6th week, and the 12th week. Participants will capture images of foods eaten and
consumed over four days (i.e., before and after images of each eating occasion). A mobile app
designed to seamlessly take images of foods/beverages will be loaded to onto each
participant's mobile telephones for free and removed at the end of the study. Physical
activity level will be assessed at baseline using a physical activity questionnaire.
Advice, support and monitoring in both diet groups Foods eaten for the IER+MED and DASH diets
will be self-selected by the participants and not provided by the study team. The IER+MED and
DASH groups will receive clear instructions on how to follow the allocated diet in a
face-to-face dietary consultation with one of the trial dietitians (45- 60 minute
appointment) at the UHCC. Both groups will receive comprehensive written instructions of how
to follow the diets at home, including recommended portion sizes and recipes and suggested
meal plans. Both groups will receive appropriate behavioral techniques to promote adherence
to diets (i.e., self-monitoring of diet and goal setting).
Participants will be contacted by telephone by an allocated dietitian one week after
randomization to check that they have started the diet, to assess understanding of the diet
and to provide any trouble shooting advice. Participants will be contacted by an allocated
dietitian with weekly phone calls in weeks 1 to 4 to discuss adherence and any problems with
the diet; and with every other week phone calls in weeks 5 to 12. Both groups will be asked
to record 4-day dietary records with the mobile food record at Week 6 and Week 11. This will
allow assessment to adherence of the allocated diets and better tailor dietary advice.
Participants will be asked to report overall compliance to the diet and physical activity
plans using a scale of 0-10 for each, on the weekly and fortnightly phone calls with the
dietitian. The IER+MED group will also be asked to record adherence to the 2-day IER using a
scale of 0-2. All participants will also be advised to become more active, walking at least
one hour per day five days per week. The intermittent energy restriction (IER) group will be
encouraged to walk on the non-IER days.
Post-Study At the end of the study all participants will be offered advice on continued
weight loss and/or weight loss maintenance if they have reached a target weight and this is
appropriate. This will include advice regarding preferred diet, i.e., IER+MED or DASH. If
resources permit, the investigators will recontact participants six and twelve months after
the end of the intervention to assess dietary intake, physical activity and body weight.
Statistical Considerations Statistical analysis will be conducted within Epidemiology
Program, UHCC. The primary aim is to determine changes in percentage visceral fat between the
IER+MED diet and the DASH diet over a 3 months period. The sample size of 25 participants per
group has been chosen to detect a difference of 15 percentage points in the reduction in
visceral fat between the two different diets, assuming an estimated 25% drop-out rate.
Calculations assume a two-sided t-test with estimated standard deviation of 10% and the
conventional 5% significance level. The primary analysis will be performed on an
intent-to-treat principle, where all participants will be analyzed by randomization group,
regardless of compliance.
The primary endpoints of visceral fat measurements will be regressed on randomization group
and time point, as well as potential confounders, using a mixed model approach accounting for
the repeated measures at baseline, and 6 and 12 weeks. The primary hypothesis will be tested
by a contrast F test comparing the difference between groups in the change from baseline to
12 weeks. The 6 month assessment will be similarly tested to understand the trend over time.
If there is evidence of a linear change in fat over time, time will be entered as a
continuous variable and the slope will be compared between groups. Visceral fat will be
modelled as an absolute area and as percentage of total area. The secondary analysis will
analyze relationship between the IER+MED intervention and total adiposity.
Ethical Considerations The study will be performed in accordance with the ethical principles
in the Declaration of Helsinki and the University of Hawaii operational and ethical
guidelines for research and other applicable regulatory requirements.
Participant information and consent Consent to enter the study will be sought from each
participant only after a full explanation has been given, information has been provided and
time allowed for consideration. The right of the participant to refuse to participate without
giving reasons will be respected.
Discontinuation and withdrawal Participants are free to withdraw from the study at any time,
without prejudice to further treatment. Participants may also be discontinued from the study
at any time, at the discretion of the investigator. Requests by the participant to be
withdrawn from the study should be made through the principal investigator.
Confidentiality After the participant has consented, any information from the study will be
stored on a secure password-protected computer that will be accessible only to the research
team. Trial data on anthropometry and activity meter data will be kept in a secure computer
at the UHCC. The food & beverage images from the 4-day mobile food records will be kept on a
secure server.
Data Handling and Record Keeping All data will be kept strictly confidential. Any individual
volunteering to participate will be assigned a code number, with the link to identifying
information only available to the few study staff that require this information. Identifying
information will be maintained in separate secure computer files from the remainder of the
data. All forms will be stored in locked file cabinets, and those with identifying
information will be stored separately from the other forms. No analysis will ever identify
participants individually.
