Thank you for your interest in this research study. The purpose of this study is to learn more about the best eating patterns for weight loss. We want to understand if time restricted eating is as effective as a standard reduced calorie diet in producing weight loss, and whether the timing of the eating window (early or late) affects weight loss or markers of metabolic health. If you join this research study, the intervention lasts for 1 year and your participation will last for up to 15 months.
You would be randomly assigned to one of three study groups: daily caloric restriction (DCR), early time restricted eating (E-TRE) or late time restricted eating (L-TRE). The E-TRE group will be asked to restrict food intake to an 8-hour window during the day, starting at 8am or 9am. The L-TRE group will be asked to restrict food intake to an 8-hour window starting at 12pm or 1pm. The DCR group will be asked to follow a traditional weight loss diet program in which they restrict calories moderately every day. You will NOT be able to choose which group you are assigned or change your group assignment.
You would attend weekly weight loss group meetings in-person and/or by videoconference for the first 14 weeks, then meetings would be held every other week for the rest of the 1-year study. These group meetings would be held on a weekday evening and last around 60 minutes. These group meetings are taught by a registered dietician and will provide support for the diet condition you are assigned. During this time participants in all three groups will receive a recommendation to gradually increase physical activity over the initial 26 weeks of the intervention to a goal of 300 min/week of moderate intensity aerobic exercise.
Before and during the 1-year intervention, you would undergo assessments of your body weight, body composition, physical activity, glucose levels, and diet and exercise behaviors.
Before you come in to learn more about the study, it would be helpful to see if you are likely to qualify to be in the study. In order to do this, we would like to ask you some eligibility questions, which will include questions about your health history, including questions about your mental health and drug and alcohol use. It should take about 15-20 minutes to go through these questions. Some of the questions may make you uncomfortable; you do not have to answer any question that you would not like to answer, but without answers to these questions, you will not be eligible to participate in the study. We will collect your name and contact information, but will use an identification code (rather than your name) on the form used to record your answers. If you do not enroll in this study, we will keep the information collected during this pre-screening secure. We are also required to give you the number of COMIRB, the Ethics Board that oversees our research: it is (303) 724-1055, in case you have any questions or concerns for them.
If you have any questions about the screening questions, please email Time2Eat@ucdenver.edu.
If you have no questions at this time, please begin answering the questions below.
Last Name
* must provide value
First Name
* must provide value
Email Address
* must provide value
Best email address to contact you
Primary Phone Number
* must provide value
Best contact phone number
Include city, state and zip code
What is the best way to contact you?
Email Primary Phone Alternate Phone
How did you hear about the study?
Date of birth:
* must provide value
Today M-D-Y mm-dd-yyyy
Gender:
* must provide value
Male Female
View equation
Current weight:
* must provide value
weight in pounds
View equation
Current height:
* must provide value
height in inches (1 foot = 12 inches)
View equation
View equation
American Indian or Alaska Native Asian Black or African American Native Hawaiian or Pacific Islander White Other
Hispanic Non-Hispanic
9. Are you a current or former tobacco user?
* must provide value
Current Former Have never used tobacco
10. If a former, when did you quit?
12. Are you planning any long-term vacations or leave of absence?
Yes No
13. How far (in minutes) do you live from the University of Colorado Anschutz Medical Campus?
* must provide value
If you have not been to the Anschutz Campus before, please use Google Maps to estimate this
14. How far (in minutes) do you work from the University of Colorado Anschutz Medical Campus?
* must provide value
If you work at UCH, Childrens', or CU-AMC campus, list 0 minutes
How many drinks of alcohol do you have in a typical week?
* must provide value
16. Do you use recreational drugs?
* must provide value
Yes No
If yes, what type of recreational drugs?
Have you participated in ANY weight loss programs or studies within the past 3 years?
* must provide value
Yes No
If yes, which program/study?
Including Colorado Weigh, State of Slim, My New Weigh, DRIFT Study, ELM study, TRF Study, TIMEX study)
Are you currently following a dietary program or planning to alter diet in the next 15 months?
* must provide value
Yes No
1. Are you currently pregnant or breast feeding?
* must provide value
Yes No
2. Have you had a baby in the last 6 months?
* must provide value
Yes No
3. Do you plan on becoming pregnant during the next 15 months?
* must provide value
Yes No
4. Do you (or are you willing to) use a reliable method of birth control for the entire 12 month study?
Yes No
Reliable methods include condoms, diaphragm, "the pill", IUD, Depoprovera, Norplant, Nuvaring, spermicide, tubal ligation, vasectomy, abstinence
Yes No
Have you undergone weight loss surgery?
* must provide value
Yes No
Including gastric bypass, gastric banding, sleeve gastrectomy, gastric balloon or pacemaker
2. What was your highest (non-pregnant) adult weight?
* must provide value
pounds
3. What was your weight 3 months ago?
* must provide value
pounds
4. Are you currently maintaining a weight loss of >50 lbs from your highest non-pregnant adult body weight?
Yes No
If yes, when (over what time frame) did you lose the weight?
If yes, how did you lose the weight?
If yes, how long have you been maintaining this weight loss?
Have you had major surgery in the past 3 months, or do you anticipate needing surgery in the next 15 months?
* must provide value
Yes No
If yes, what type of surgery?
Have you used prescription weight loss medications or over the counter weight loss supplements in the past 6 months? (including: semaglutide (Ozempic or Wegovy), Liraglutide (Saxenda), Contrave, Alli, Xenical, or Qsymia (phentermine/topiramate or phentermine alone)
* must provide value
Yes No
If yes, when did you start taking it?
Today M-D-Y
If yes, are you currently still taking it?
Yes No
If no, when did you stop taking it?
Today M-D-Y
Have you been doing this for the last 6 months?
Yes No
Are you currently participating in or planning to participate in any formal weight loss, including physician directed weight loss, or physical activity programs?
* must provide value
Yes No
Are you currently participating in or planning to participate in any other research studies or clinical trials?
* must provide value
Yes No
Does your job require you to work during the night, swing shifts, or work during late shifts that may make exercising at a certain time of day difficult?
* must provide value
Yes No
1. Do you have a Primary Care Physician?
* must provide value
Yes No
If no, do you have access to a health care professional if you need medical care?
Yes No
If no, are you willing to establish care with a PCP or health care professional before beginning the study?
Yes No
2. Do you have any medical conditions?
Yes No
3. Please List ALL Medical conditions. Please report ALL medical conditions so we can accurately determine if you are eligible for the study:
4. Do you take any medications on a regular basis?
Yes No
5. Please List ALL Medications. Include the frequency, dose and reason for taking medication so we can accurately determine if you are eligible for the study:
Include frequency, dose, reason for taking medication, and reason for stopping medication
6. Have you stopped taking any medications in the last year?
Yes No
Include frequency, dose, reason for taking medication, and reason for stopping medication
1. Diabetes (Type 1 or 2)?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
2. Heart problems including coronary artery disease, heart attack, chest pain or angina, heart stent or bypass, heart valve problems, congestive heart failure, abnormal ECG, abnormal stress test?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
3. Heart arrhythmia (irregular heart rhythm) such as ventricular tachycardia or atrial fibrillation?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
4. Hypertension (high blood pressure, >140/90)?
Yes No
If Yes, is your blood pressure now controlled?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
5. Lung problems such as asthma, COPD, cystic fibrosis, pulmonary embolism, severe shortness of breath, or any condition requiring the use of oxygen?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
6. Neurologic (brain) disease including stroke, transient ischemic attack, multiple sclerosis, or seizure?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
7. Cancer, HIV infection, or blood disorder?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
8. Thyroid disease or high cholesterol?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
9. Liver, kidney, or gastrointestinal (digestive) problems including kidney stones?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
10. Arthritis or other bone, joint or muscle disorder?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
11. Psychiatric or mental health problems (such as depression, bipolar, psychosis, or schizophrenia?)
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
12. Eating disorder such as anorexia, bulimia, or binge eating disorder?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
13. Problems with current or past alcohol or drug abuse?
Yes No
If yes, please explain. I.e diagnosis date, symptoms you experience, recent test results, medications used for treatment if applicable, etc.
1. What is your usual bedtime on weekdays?
Now H:M Use 24 hour time clock (ie: 9:00pm = 21:00)
2. What is your usual wake time on weekdays?
Now H:M
3. What is your usual bedtime on weekends?
Now H:M Use 24 hour time clock (ie: 9:00pm = 21:00)
4. What is your usual wake time on weekends?
Now H:M
5. Have you ever worked the night shift?
* must provide value
Yes No
6. What hours did you work on the night shift?
Use 24 hour time clock (ie: 9:00pm = 21:00)
7. How many days per week did you work the night shift?
8. How long (months or years) did you work night shifts?
9. What month and year did you stop doing night shift work?
Today M-D-Y
1. Which meals do you regularly eat? (Check all that apply)
2. When do you snack? (Check all that apply)
3. On a typical weekday, what time do you start to eat or drink anything with calories (including snacks)?
* must provide value
Now H:M
4. On a typical weekday, what time do you finish eating or drinking anything with calories (including snacks)?
* must provide value
Now H:M Use 24 hour time clock (ie: 9:00pm = 21:00)
5. On a typical weekend day, what time do you start to eat or drink anything with calories (including snacks)?
* must provide value
Now H:M
6. On a typical weekend day, what time do you finish eating or drinking anything with calories (including snacks)?
* must provide value
Now H:M Use 24 hour time clock (ie: 9:00pm = 21:00)
7. Participation in this study would require that you own a smartphone. Do you own a smartphone?
* must provide value
Yes No
If, yes, is your smartphone based on an iOS (Apple) or Android operating system?
iOS (Apple) Android
Do you anticipate anything that might limit your ability to complete the study visits in this 1-year research study? The study involves 2-3 weekday visits at baseline and 1-2 visits at weeks 14, 26 and 52 to assess your body weight, body composition, sleep, diet and exercise behaviors.
* must provide value
Yes No
Do you anticipate anything that might limit your ability to regularly attend the virtual weight loss group meetings? The meetings are held weekly for ~3 months then every other week for the rest of the year. The meetings are held on weekday evenings and last approximately 60-90 minutes.
* must provide value
Yes No
Do you anticipate anything that might limit your ability to increase your exercise level during the 12 month intervention? The study involves gradually increasing aerobic exercise to 300 minutes per week during the study. Exercise will be of moderate intensity, and the primary form of exercise recommended will be walking. The exercise will be performed on your own and will not be supervised.
* must provide value
Yes No
Are you willing to abstain from participating in any other weight loss or physical activity programs or research studies during the entire duration of the study? This includes visits with a weight management medical provider and/or visits with a registered dietitian (nutritionist) for the purpose of weight loss.
* must provide value
Yes No
Are you willing to abstain from taking over the counter or prescription weight loss medications during the entire duration of the study?
* must provide value
Yes No
Are you willing to be randomized to any of the 3 study groups (early time restricted eating, late time restricted eating or daily calorie restriction)? Remember, you cannot choose or change the group you are assigned to, and you will be asked to maintain this eating pattern for the entire 12 months of the intervention.
* must provide value
Yes No
If you are assigned to either of the Time Restricted Eating groups, do you anticipate anything that might limit your ability to perform an extended fast (eat only during a 8 hour window during the day and fast for 16 hours) for the duration of the 12 month intervention?
* must provide value
Yes No
Thank you for answering our pre-screening survey! A study staff member will reach out when with next steps!