Native Hawaiian and other Pacific Islanders (NHPI) from Polynesia, Micronesia, and Melanesia are the fastest growing racial/ethnic group in the U.S., but are vastly underrepresented in health research. NHPIs experience major disparities in risk of breast, colorectal, and endometrial cancers, and worse cancer-free survival, particularly among younger adults. There has been a concerning increase in cancer incidence and deaths among NHPIs in recent years in parallel with persistent or widening health disparity gaps in cancer risk factors like poor diet quality, obesity, diabetes, and access to healthcare. Identifying culturally tailored ways to address cancer risk factors in the NHPI community is therefore an urgent unmet need.
Diet is a cornerstone of managing metabolic health for cancer prevention. Irregular meal timing can disrupt 24-hour circadian clock-regulated metabolism to promote metabolic dysfunction, whereas structured mealtimes realign circadian transcriptional programs to improve metabolic health. Time restricted eating (TRE) is a form of intermittent fasting where daily calories are eaten within 6-12 hours. TRE improves cancer risk factors including hyperinsulinemia and dyslipidemia, but has not been evaluated in NHPIs. The investigators conducted a pilot 6-month randomized, controlled, crossover trial to test the feasibility and acceptability of TRE for effects on metabolic health in NHPIs at risk of endometrial cancer (TIMESPAN, NCT04763902). TIMESPAN was designed with feedback from focus groups and the Community Advisory Board (CAB) of NHPIs. Participants received isocaloric, culturally tailored, pre-prepared meals to control underlying diet during TRE and control. Insulin/c-peptide, triglycerides, and blood pressure improved with each phase, but TRE had larger effects and improved mood, energy, and satiety. The prepared meals addressed food insecurity and educated participants on healthy eating and portion control, goals of Medically Tailored Meals (MTM). A limitation was that the investigators did not measures effects of TRE without diet control. Since communal eating is integral to NHPI customs,13 participants reported that not providing family meals was a barrier.
The investigators propose to provide family meals and include a TRE arm without diet control in the, "Family-Based Meal Timing for Cancer Prevention among Native Hawaiian and other Pacific Islanders: FAMTIME" study. The long-term goal of this study is to address cancer risk disparities in NHPIs using diet strategies. The investigators will recruit 10 NHPI females at risk of obesity-related cancer (i.e., hyperglycemia, dyslipidemia, overweight/obese, history of diabetes, or cancer precursor lesions) who fast \<12-hrs/day. Participants will complete a 2-week run-in period, then be randomized to 8-weeks' of (1) Control, (2) MTMs (healthy Polynesian diet), (3) TRE with usual diet, or (4) TRE + MTMs. Participants will also complete a 6-month follow-up. Family social support via communal eating will be encouraged. The myCircadianClock (mCC) app will evaluate and promote compliance. The central hypothesis is that MTM and TRE will improve metabolic and mental health among NHPI females at risk of obesity-related cancer; MTM+TRE will be multiplicative.
Aim 1. Determine the feasibility, fidelity and preliminary acceptability of TRE and MTM among Pacific Islander women at risk for developing endometrial cancer. Participants will be randomized using stratification by age group and BMI category to balance groups according to those variables. Feasibility will be evaluated by: (1) Proportion (%) of women referred that were recruited and consented; (2) attrition as a function of time; (3) % of scheduled biospecimen collections and questionnaires completed; (4) number of TRE or MTM adherent days per week (participants will be considered adherent if they fasted between 14-18 h per day during the TRE phase according to mealtime log); (5) % meals delivered on schedule. The study will be considered feasible if \>70% women are consented and retained, complete all biospecimen collections and questionnaires, and if women adhere to the TRE protocol for at least 5/7 days per week. Fidelity will be evaluated as % protocol checklist items delivered as intended with a goal of 90%.
Aim 2. Compare TRE, MTM, TRE + MTM, and Control for effects on metabolic cancer risk factors among NHPI women at risk of obesity-related cancer. Primary outcome: hyperinsulinemia (C-peptide). Secondary outcomes: waist/hip ratio, weight, body composition, c-reactive protein, fasting glucose/insulin, 24-hour glucose, HOMA-IR, atherogenic lipids, blood pressure, blood metabolites related to cancer risk, appetite, diet quality, sleep quality/duration, and physical activity.
Aim 3. Compare TRE, MTM, TRE + MTM, and Control for effects on emotional wellbeing among NHPI women at risk of obesity-related cancer. Focus groups and the CAB reported that mental wellbeing is the most important outcome to NHPI women, yet it is rarely discussed or evaluated. The primary outcome is depression (PHQ-9). Secondary outcomes: anxiety, alcohol use, health status, social support, and acculturative stress. These outcome measures were endorsed by the CAB as being particularly relevant.
Aim 4. Qualitatively investigate the roles of social support and mental health in diet behavior change among NHPI women at risk of obesity-related cancer and their household. The investigators will build upon the themes that emerged from TIMESPAN by conducting focus groups among (1) FAMTIME participants and their household members, (2) the CAB, to interpret outcomes and evaluate the intervention from a cultural perspective. The investigators will explore in-depth the roles of social support, mental health, and food security in behavior change, and how to optimize cancer prevention interventions for high impact in the NHPI community.
