Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT04836312 |
| Other study ID # |
844153 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
July 12, 2021 |
| Est. completion date |
August 28, 2022 |
Study information
| Verified date |
February 2023 |
| Source |
University of Pennsylvania |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
This pilot study will randomize 34 patients with hypertension and obesity to either
time-restricted feeding alone or a commitment device to encourage time-restricted feeding,
including a commitment pledge, involvement of a supportive partner, setting of implementation
intentions, and multiple daily reminder text messages. The intervention will last 12 weeks,
followed by a 6-week follow-up period. The primary outcome is adherence to the IF regimen,
captured via daily text message, over 18 weeks
Description:
1.1. Non-Pharmacologic Interventions to Improve Blood Pressure Control: Despite the wide
availability of multiple classes of antihypertensive agents, compelling data that blood
pressure (BP) lowering reduces mortality and cardiovascular events, and decades of public
health campaigns, half of American adults with hypertension do not achieve adequate BP
control. Randomized controlled trials of interventions to improve BP control in patients with
hypertension have largely focused on home blood pressure monitoring, nurse- or
pharmacist-lead education and medication titration, and/or financial incentives. Though many
of these interventions improve short-term blood pressure control, they are cost-additive to
health systems, post-intervention data is mixed, and none have been widely implemented.
Though consensus guidelines recommend dietary changes to improve hypertension control, with a
particular recommendation in favor of the DASH (Dietary Approaches to Stop Hypertension)
diet, very few U.S. patients adhere to this complex dietary pattern. The DASH diet reduced
systolic BP (SBP) by 11 mmHg in randomized controlled trials in which participants were
provided with food, and 4 mmHg in a study testing a 6-month, 18-visit intensive lifestyle
intervention intended to promote the DASH diet; however, BP control was not sustained 12
months after the end of the intensive intervention.
1.2. Effect of Intermittent Fasting on Metabolic Parameters: In contrast to the DASH diet,
intermittent fasting (IF) is a dietary pattern that emphasizes temporal restriction of
caloric intake rather than restricting the number of calories and/or changing the types of
foods eaten. The simplest and most popular variation of IF involves restricting caloric
intake to an 8-hour period each day, and consuming no calories for the other 16 hours
(so-called 16:8 time-restricted feeding). In animal studies, IF has been shown to activate
cellular pathways with potential disease-modifying benefits in a number of conditions. In
small human studies, IF is associated with a reduction in SBP by 5-10 mmHg, LDL cholesterol
by ~8 mg/dl, and weight by ~ 3 kg, though none of the studies of a time-restricted feeding
regimen included concurrent controls. Some patients report that IF is easier to initiate and
maintain than other dietary patterns, though this has not been tested empirically.
1.3. Commitment Devices to Promote Healthy Behaviors: Commitment devices are centered in
theoretical research that posits a planner-doer framework, wherein an individual can be
conceptualized as dual sub-selves: The planner, who cares about long-term well-being; and the
doer, who cares only for the present and prioritizes immediate payoffs. Conflict between the
motivations and priorities of the planner and the doer sub-selves results in failure to
follow-through with a plan when the moment to act arrives. Commitment devices are mechanisms
by which the planner sub-self constrains the actions of their future doer sub-self by making
certain choices more costly. Hard commitments impose a financial penalty for failing to
follow through on the commitment, and soft commitments impose a psychological penalty. Hard
commitments have been shown to change health behaviors, as in a study where smokers forfeited
money deposited in a savings account if they failed to quit smoking after 6 months. However,
monetary losses may not be attractive to many people, and effective soft commitment devices
may be more appealing.
Pre-clinical research suggests that both intra- and interpersonal commitments might be useful
components of a soft commitment device. Intrapersonal commitments have also been framed as
implementation intentions, or specific plans as to where, how, and/or when an action will be
taken. In small experiments, smokers who set a quit date were more likely to quit, and
college students who set a date and time to visit a vaccination clinic were more likely to
receive their vaccination. Interpersonal commitments leverage social networks, so that the
penalty involves letting down a support partner. Involvement of social networks has been used
to increase physical activity and improve control of weight and blood glucose in patients
with obesity and diabetes. Social networks have been used explicitly within the context of
commitment devices to encourage deposits in a savings account in a study of Chilean
micro-entrepreneurs who either attended or did not attend a weekly peer support group
meeting. Weight loss studies encouraging participants to exercise and change their eating
behavior have employed commitment devices, including some that leveraged the involvement of
family members or friends of the participant, with mixed results.
1.4 Rationale for the IFAST Study: The IF dietary pattern, though not inspired by behavioral
economic concepts, is structured to take advantage of them and thus may be particularly
amenable to a robust commitment device intervention. Changing one's eating patterns to a
complex new diet is a cognitively intense process that requires active consideration of
complex information multiple times per day, leading to cognitive overload and impaired
decision-making. By contrast, IF, especially time-restricted feeding, is cognitively very
simple. This simplicity may help participants avoid cognitive overload, initiate the dietary
pattern and adhere over the long term.
This study seeks to test how a robust soft commitment device, incorporating both intra- and
interpersonal commitments, affects uptake and adherence to an intermittent fasting dietary
pattern, as compared with control, in patients with obesity and hypertension
