The Effect of Time Restricted Feeding on Fat Mass in Overweight Women

Participants will complete a one-month intervention where they are will restrict their daily food intake to an 8-hour time period, i.e., between 1200 to 2000 hours. During the remaining 16-hour intermittent fasting period (2000 to 1200 hours) participants will be allowed to drink zero calorie beverages (diet soda pop, black coffee, tea, water, etc) in order to maintain normal hydration. There will be no attempt to restrict food intake. Rather simply to restrict the time period each day when food is consumed. Participants' body mass, fat mass, and non-fat mass will be monitored non-invasively using a weigh scale and densitometry via air displacement (Bod Pod) at 0, 2 and 4 weeks following the dietary intervention. Also, participants will be interviewed following the final body composition measure to assess whether or not they continued to follow the intermittent fasting approach.

Study Overview

• Status: Unknown
• Conditions: Weight Loss
• Intervention / Treatment: Behavioral: Time restricted feeding

Detailed Description

Participants (16 overweight women, BMI (Body mass index) ˃25, ages 18- 30 y)will complete a one-month intervention where they will restrict their daily food intake to an 8-hour time period, i.e., between 1200 to 2000 hours. During the remaining 16-hour intermittent fasting period (2000 to 1200 hours) participants will be allowed to drink zero calorie beverages (diet soda pop, black coffee, tea, water, etc) in order to maintain normal hydration. There will be no attempt to restrict food intake. Rather simply to restrict the time period each day when food is consumed. Participants' fat mass will be monitored non-invasively using densitometry (with a Bod Pod) prior to and following a 4 week intervention where the participants will eat their normal daily intake during an 8-hour period each day (1200 to 2000 hours). The Bod Pod measures body volume via air displacement and together with an accurate measure of body mass enables body density to be calculated (Density = mass/volume). Satisfaction, hunger, and fullness with the diet will be monitored on a weekly basis using a validated visual analog scale (Flit et al, 2000). Adherence to the diet will also be assessed on a weekly basis as the number of days the diet was followed. During the 16-hour fasting period participants will be able to drink as much of zero calorie beverages as they desire. On day 2, 7, 14, 21, & 28 participants will return to the lab at 8am (following a 12 hour fasting period) and both the acidity of their urine (using a urine dip stick) and their blood sugar (using a glucometer) will be tested. Following one month the participants will be allowed either to continue this eating pattern or revert to their prior 3 meal intake. After a month of self-regulation, the participants' fat mass will be measured again using the Bod Pod.

• Study Type: Interventional
• Enrollment (Anticipated): 16
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • London, Ontario, Canada, N6A 3K7
      • Recruiting
      • Exercise Nutrition Research Laboratory, Western University
      • Principal Investigator: Peter Lemon, PhD
      • Contact: Peter Lemon, PhD; Phone Number: 88139 519 661 2111; Email: plemon@uwo.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Asymptomatic participants between the ages of 18-30 years with body mass index ˃25 will be studied

Exclusion Criteria:

• Diabetic
• Pregnant
• Individuals with a history of fainting
• Low blood sugar
• Heart disease, migranes, or heart burn
• Participants less then 18 of age
• Anyone who for health or performance reasons should not skip breakfast will be excluded. These will be assessed by self report

Study Plan

How is the study designed?

Design Details

• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Intermittent fasting group; Participants will restrict their daily food intake (time restricted feeding) to an 8-hour time period between 1200 to 2000 hours. During the remaining 16-hour intermittent fasting period (2000 to 1200 hours) participants will be allowed to drink zero calorie beverages (diet soda pop, black coffee, tea, water, etc) in order to maintain normal hydration. There will be no attempt to restrict food intake. Rather simply to restrict the time period each day when food is consumed.

Behavioral: Time restricted feeding; Participants will consume their daily calories only between 12:00 and 20:00 for 4 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fat mass change over 4 weeks period of intervention	Body fat mass change (%) will be measured using BodPod over the course of 4 weeks at 0, 2 and 4 weeks	4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Non-fat mass change over 4 weeks period of intervention	Body non-fat mass (lean mass) (%) will be measured using BodPod over the course of 4 weeks at 0, 2 and 4 weeks	4 weeks
Urine acidity change over 4 weeks of intervention	Urine acidity will be measured following a 12 hours fasting at 0800 using a urine dip stick on days 2, 7, 14, 21, & 28	4 weeks
Blood sugar change over 4 weeks of intervention	Fasted blood sugar will be measured following a 12 hours fasting at 0800 using a finger prick glucometer (Free Style Lite) on days 2, 7, 14, 21, & 28	4 weeks
Diet satisfaction change over 4 weeks of intervention	Diet satisfaction will be monitored on a weekly basis using a validated visual analog scale (Flit et al, 2000)	4 weeks
Feeling of hunger change over 4 weeks of intervention	Hunger will be monitored on a weekly basis using a validated visual analog scale (Flit et al, 2000)	4 weeks
Feeling of fullness change over 4 weeks of intervention	Feeling of fullness will be monitored on a weekly basis using a validated visual analog scale (Flit et al, 2000)	4 weeks

Collaborators and Investigators

• Sponsor: University of Western Ontario, Canada

Study record dates

Study Major Dates

• Study Start: January 1, 2016
• Primary Completion (Anticipated): April 1, 2016
• Study Completion (Anticipated): April 1, 2016

Study Registration Dates

• First Submitted: December 10, 2015
• First Submitted That Met QC Criteria: December 11, 2015
• First Posted (Estimate): December 14, 2015

Study Record Updates

• Last Update Posted (Estimate): January 20, 2016
• Last Update Submitted That Met QC Criteria: January 18, 2016
• Last Verified: January 1, 2016

More Information

Terms related to this study

• Keywords: Weight Loss; Intermittent fasting
• Additional Relevant MeSH Terms: Body Weight; Body Weight Changes; Weight Loss; Overweight
• Other Study ID Numbers: 107401

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO