Yes, you can send multiple food items at a time. See “How do I log what I eat or drink?” for more information.

Yes, caffeine and other zero calorie beverages, such as diet sodas, teas, and coffee, still count. Caffeine affects your brain and metabolism. Research still needs to be done to understand what effect caffeine will have on a time-restricted diet. However, in all studies performed to date, only water was available outside of the designated eating interval.

If you want to delete an annotation, simply long-press the item in the list area (above the text entry field, not below) and you will be prompted to delete that item.

Once an item is saved, it cannot be deleted or altered. We do expect a certain level of recording error, so don’t panic if you saved something by mistake or with incorrect information. Just double check future entries before saving.

Yes, you can always send data after the fact, so if you forget to take photos or record something, don’t worry. Send according to the following steps:

Step 1:

Go to the main photo screen and click on the annotation icon (the 3-line icon in the bottom right of that screen).

Add new annotations in the Enter Annotation field or select from the available list of items.

Select how long ago you had this item.

Click on Send button. The same process can be used to record medicines and water, just select the appropriate category at the top of the annotation screen.

A Feedogram is a timeline of all food, beverages, water, and medicines/supplements you have recorded. The green marks represent food and beverages, red represents water, and orange represents medication/supplements. This snapshot is an easy display of when and what we put into our stomach. Touching any of these marks also shows you the items. Below the "Feedogram" is a horizontal green bar showing the average time window in which you typically eat all your food and beverages during weekdays. The orange bar below it shows the eating window during the weekend. Research has shown eating within a shorter window of 8-12 hours everyday can reduce body fat, improve sleep and may have many health benefits. You can set an eating window during which you wish to eat by clicking on the "Set Target button". The target window is shown within a yellow box on the Feedogram and a blue bar below it. To see previous week’s eating window summary, tap on the “History” button. Water and medications/supplements are not considered as food/beverages, so you may continue to drink water and take your supplement/medications as suggested by your physician or pharmacist.

The Feedogram will become available at the end of your 14-day baseline period. Once it appears, you can review your eating patterns and select a target interval during which you may try to eat all your food and beverages.

When you will click on the Feedogram menu you will find different colored marks on it. These represent different food types. If you have logged an item of "Food"/"Beverage" type you will find a Green mark on the Feedogram. If you have logged "Medicine/supplement" or "Water" you will find an Orange or Red mark, respectively. Touch on a mark in the feedogram. The particular food/beverage/medicine/water image will be enlarged along with the name, date and time. If data was saved by text entry only, then only the name, date and time will be displayed.

A Menu Medley is a visual representation for text data. The importance of each word displayed will correlate with its size or color (larger words appear more often in your diet).

To get to the menu medley, first go to your Feedogram, so your screen should look like this:

Click on the history button on the bottom left of the screen. Screen should look like this:

If you click on any of the weeks (bars) you will be able to see the menu medley for that week. It will look like this:

If you click on the list in the top right hand corner, it will show you what your logged and how many times you logged it that week.

Activity level implies the rigor of your exercise. Here you can refer the following colors for different levels Green for light, Orange for moderate, and Red for intense.

Yes, you can log previous exercise the same way you would if you just worked out. Just set the time and date of when you exercised. See “How do I log my exercise?” for more information.

The exercise chart tracks the dates and durations of your exercise. In order to view your exercise chart, click on the icon of the biker with a graph located at the top of the home screen. You will find the exercise chart with different color legends and clicking on a specific legend will show you the details. You can also select the monthly and yearly tabs to view the previously entered records. Note, you will not be able to view the exercise chart until you completed your 2-week baseline period.

Data from Google Fit or the Apple Health Kit are automatically synced with the myCircadianClock app. If you have another device, such as a smartwatch or activity tracker, simply sync it with Google Fit or Apple Health Kit and the information will automatically be synced with the mycircadianclock app.

Fitbit does not currently sync with Google Fit or the Apple Health Kit. There is an app called Sync Solver that will sync data from Fitbit with the Apple Health Kit, but does not sync it to Google Fit. We have no affiliation with Sync Solver and do not endorse the use of their app.

BMI stand for Body Mass Index. It is used as a generalized standard to assess weight and in relation to your height. To calculate your Body Mass Index:

Go to the main menu and select the "Track Your Health” tab.

Click on the BMI Calculator submenu.

Tap on the Height button and enter your height in feet and inches. Similarly, tap the weight button to enter your weight in pounds.

As soon as you enter both the fields, the "Calculate" button will be activated and clicking on that button will save the data automatically and a marker will be placed at the appropriate level in the scale.

The BMI chart displays your recorded BMI values, allowing you to track change over time. To view your BMI chart, click on the graph icon present at the top left corner of the BMI page. You can also select the monthly and yearly tabs to view previously entered records.

The app does not measure your blood pressure. You may measure your blood pressure using a blood pressure monitor and then record the values in this app. Follow the steps below to record your blood pressure.

Select "Track your Health" from the main menu.

Click on the Blood pressure submenu.

In the blood pressure page you will find two fields, Systolic and Diastolic.

Click on Systolic for a pop-up window to appear where you can enter your Systolic value. Select Diastolic to enter your Diastolic value the same way.

When you will enter values for both fields the "Save" button will be enabled. Clicking on that button will automatically save your blood pressure and this level will be displayed in the scale accordingly.

For more information on how to interpret your blood pressure, select the information icon in the top right of the blood pressure screen.

When your heart beats, it contracts and pushes blood through the arteries to the rest of the body. This force creates pressure on the arteries. This is called systolic blood pressure. It is the top number on your blood pressure reading. A normal systolic blood pressure is below 120 mmHg.

The diastolic blood pressure number or the bottom number indicates the pressure in the arteries when the heart rests between beats. A normal diastolic blood pressure number is less than 80 mmHg.

The MyCircadianClock app is only a tracking device. Please consult with your doctor if you have any questions or concerns.

Click on the graph icon at the top left corner of the blood pressure screen. It will lead you to the "Blood pressure chart" page. This chart displays your recorded Systolic and Diastolic values and allows you to monitor any changes.

The app does not measure your blood sugar. You may measure your blood sugar using a blood sugar monitor and then record the values in this app. You can record your blood sugar value each time you measure using the following steps:

Select "Track your Health" from the main menu.

Click on the Blood Sugar Submenu.

Select when you measured your blood sugar.

You can enter your blood sugar value by tapping on the respective field and pressing the "Save" button to log your value.

The blood sugar chart displays your recorded blood sugar values, allowing you to track any changes over time. In order to view your records, click on the graph icon at the top left corner of the Blood Sugar page. You can also select the monthly and yearly tabs to view the previously entered records.

A majority of research on time-restricted feeding has been done in flies and mice. We have also run preliminary studies in humans. Potential benefits include:

• Weight loss
• Decreased cholesterol
• Decreased blood pressure
• Decreased blood sugar
• Decreased A1c
• Better sleep quality
• Increased Alertness
• Increased Endurance
• Decreased body fat

In order to obtain sufficient data, we ask that you use the app for a total of 14 weeks. The first two weeks are a baseline period in which time you will start using the app to log your current eating, sleeping, and activity patterns. At the end of the baseline period, you will receive a report that summarizes your lifestyle. Throughout the next 12 weeks of the study, you will continue to document your daily behaviors, but you can also set your own goals for timing of eating and sleeping. You will be able to view your history anytime through the app.

Eating within an 8 to 12-hour interval is part of a healthy lifestyle and should continue through your life. You are more than welcome to continue to use the app beyond 14 weeks. 14 weeks is a short amount of time that is still sufficient to see most benefits and get usable data.

Yes, you can use the app offline, but you won’t be able to view the Feedogram or history in offline mode.

You can add reminders by selecting the “Self Reminder” tab from the menu in the top left corner of the home screen. Reminders can be used for anything you choose. Common reminders are to take medication or supplement, appointments, or to remind you of you eating, sleeping, or activity goals.

Select the "Self Reminder" tab from the main menu

Click on the "+" icon at the top right corner.

Enter the name of the reminder, the time you’d like to be reminded, and how often you should be reminded. An alarm will ring on the set day and time with your reminder note. Reminders can be set to repeat on a regular basis or for individual events.

At the end of your two week baseline period, you can review what, when, and how much you ate in the "Feedogram" tab. You may also review your sleeping patterns, exercise, and daily step counts as sensed by the phone. After reviewing your own data on daily pattern of activity, sleep and food, you may decide to change these daily behaviors. It is entirely up to you to make any change or just continue with your current daily routine. In the subsequent 12 weeks, you will know if you made any lasting change and whether it had any impact on your health. Some changes may be as simple as taking your supplements/medications at the right time, walking a few hundred steps extra, avoiding late night eating, or sleeping an extra 15min.

You can set an eating window during which you wish to eat by clicking on the "Set Target button" in the Feedogram tab. The target window is shown within a yellow box on the Feedogram and a blue bar below it. To see previous week’s eating window summary, tap on the “History” button. Water and medications/supplements are not considered food/beverages. Therefore, you may continue to drink water and take your supplement/medications as suggested by your physician or pharmacist.

We do not provide specific goals for eating, sleeping, or activity. It is up to you to determine goals that you feel are best for your health and your lifestyle.

Our research in animal models has shown that eating and drinking within an 8 to 12-hour interval has a wide variety of health benefits. Another way of thinking about this is that your body needs to fast for ~12 to 16-hours per day. We do not yet know the exact eating interval that is needed to see the full effects in humans. In preliminary trials in humans, health benefits were observed when eating was restricted to a 10 to 11-hour eating/drinking interval per day.

Your chosen eating interval should also take into account your baseline eating interval. For example, if you were currently eating over a 16-hour interval, you would likely see benefits from switching to a 12-hour interval. If you are already eating between a 12 or 13-hour interval, you may need to switch to a 10 or 11-hour eating interval goal to see health benefits.

For more information about research from our lab and others, please see the blog and science sections on our website, www.mycircadianclock.org.

Yes. A healthy lifestyle is determined by when, what, and how much you eat, sleep, and move. Timing of caloric intake is only one of those components. When you eat is a very important aspect that is frequently ignored. If all you change is the timing of your food, it should still have a beneficial effect, but it would be optimal to eat healthy proportions and quality of food. For example, in mice, we found that mice on an 8 to 12-hour eating interval did not gain weight when put on a high fat diet. However, mice that stuck to an 8 to 12-hour eating interval on normal diet were still healthier than the mice on the high fat diet.

Determine the start and stop times of your eating and drinking that best fit your schedule. The exact times vary greatly depending on the individual. It is a good idea to not eat or work out too close to when you plan on falling asleep, but aside from that, figure out what works for you and do your best to stick to it. You can update your target interval and timing at any time.

Example: If you were to set a goal of a 11-hour eating interval, and your first drink or sip (of anything but water and medicine) was at 7am, then your last drink or sip would be at or before 6pm. After 6pm, you would only be able to have water and medications. This schedule would allow for an 11-hour feeding interval and a 12-hour fasting interval.

Your body digests food differently throughout the day due to biological rhythms in your digestive system. Your liver is best at processing high calorie foods in the first half of the day. Therefore, when you eat a large meal or dessert late in the day, not only is your liver not capable to digesting it well, but it is also likely that you will not be very active until the next day. Eating higher calorie meals in the first half of the day allows your body to digest the food better and gives you time to use those calories with your daily activity.

The optimal timing and duration of sleep depends on each individual’s sleep needs, schedule, and internal biological rhythm. The amount of sleep needed changes across your lifespan, but for adults (18 years or older) it is suggested to get 7 to 9-hours of sleep per night. Please consult a doctor for sleep and health advice.

You can set sleep goals by clicking on the Set Target button. You will be prompted to enter your goal 'start' and 'end' times for sleeping. The target will be displayed like a border line on the chart.

There is no one exact time that you should or should not exercise. Here is some information you may want to keep in mind when you determine when and how much you plan to exercise:

• There is a sharp rise in heart rate in the early morning (~6:45 am, this time will vary based on schedule) due to a peak in cortisol to help you wake up.
• Muscles have the best coordination in the afternoon around 2:30 pm.
• Muscles have the fastest reaction time around 3:30pm.
• Cardiovascular efficiency and muscle strength is greatest around 5pm.
• Blood pressure is highest around 6pm.
• Exercise arouses the brain, so it is good to stop vigorous activity a few hours before you plan to sleep.

You should consult a doctor about intensity, duration, frequency, and types of exercise that are best for you.

The American Heart Association Recommendations are below.

For Overall Cardiovascular Health:

• At least 30 minutes of moderate-intensity aerobic activity at least 5 days per week for a total of 150 OR
• At least 25 minutes of vigorous aerobic activity at least 3 days per week for a total of 75 minutes; or a combination of moderate- and vigorous-intensity aerobic activity AND
• Moderate- to high-intensity muscle-strengthening activity at least 2 days per week for additional health benefits.

For Lowering Blood Pressure and Cholesterol:

• An average 40 minutes of moderate- to vigorous-intensity aerobic activity 3 or 4 times per week