Overnight Fasting After Completion of Therapy: The OnFACT Study

Status

Active, not recruiting

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT03523377

Enrollment

Registered

2018-05-14

Start date

2018-04-27

Completion date

2026-04-30

Last updated

2025-07-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Childhood Cancer Survivors

Keywords

Fasting, 18-199

Brief summary

The purpose of this study is to test whether regularly not eating for at least 14 hours overnight (intermittent fasting) is feasible and can improve blood sugar.

Interventions

OTHERprolonged overnight fasting

Three phone calls using motivational interviewing, support via SMS text.

OTHERusual care

Eat a heart-healthy diet and exercise for at least 30 minutes five days a week

Study design

Allocation

RANDOMIZED

Intervention model

SINGLE_GROUP

Primary purpose

PREVENTION

Masking

NONE

Intervention model description

The OnFACT study is a pilot randomized controlled trial of prolonged overnight fasting among adult survivors of childhood cancer.

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Body mass index is ≥ 18.5 kg/m\^2 * History of treatment for cancer or related illness diagnosed at ≤ 25 years old * Off cytotoxic therapy for primary cancer ≥ 2 years * Not receiving cytotoxic therapy (chemotherapy, external beam radiation therapy) at the time of study enrollment * History of radiation to the chest, abdomen or total body * Current age ≥18 years * English-speaking * Personal phone with SMS text messaging capability * Willingness to wear an mHealth device, such as a FitBit, for two 7-day periods * Able to perform all study requirements

Exclusion criteria

* Use of any antidiabetic, weight loss, or appetite control medication * Use of any other medication that could impact dietary intake, such as prednisone * Currently fasts 12 hours or more by self-report * Unable to fast due to medical reason such as pregnancy

Design outcomes

Primary

Measure	Time frame	Description
Participation completion	6 months	Proportion of registered participants who successfully complete the 6-month intervention

Secondary

Measure	Time frame	Description
measure of glucose metabolism	6 months	Assess the effect of prolonged overnight fasting on glucose metabolism, measured by glycosylated hemoglobin (HbA1c).

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026