Food · Lots of talk
Intermittent fasting / 16:8
Also called 16:8 · time restricted eating · TRE · IF · eating window · fasting window
Community talk. May contain inaccuracies. Not medical or health advice. No result or safety is promised.
Intermittent fasting limits when you eat. The daily 16:8 version puts meals into eight hours, followed by 16 hours without calories. People use it to simplify eating and reduce snacking; food quantity and quality still matter.
Cleveland Clinic · 202601
How the daily eating window works
The 16 hours include sleep. An 11 a.m.–7 p.m. eating window leaves the overnight hours and the following morning without food. Other schedules move those hours earlier or later. This daily pattern is called time-restricted eating; alternate-day fasting and 5:2 are different approaches.
Cleveland Clinic · 2026Drinks count toward the window too. The usual calorie-free period allows water, black coffee and unsweetened tea. Milk, cream, sugar and other calorie-containing additions belong inside the eating hours.
Cleveland Clinic · 2026The meals still need to nourish you. 16:8 does not specify a menu. Protein foods, vegetables, whole grains and other nourishing foods still matter. Large meals and frequent snacks inside the window can replace the calories skipped earlier, so eating for fewer hours is not automatically eating less.
Johns Hopkins Medicine · 202602
Potential benefits
A weight-loss option without calorie logging. In studies described in an NIDDK interview, a shorter eating window helped people eat less. A yearlong comparison in adults with obesity found roughly 5% weight loss with either time-restricted eating or daily calorie restriction.
NIDDK · 2024Blood sugar may improve in supervised diabetes care. A six-month trial in adults with obesity and type 2 diabetes found that an eight-hour window lowered A1C, a measure of longer-term blood sugar, similarly to calorie restriction. Participants had medication management and regular follow-up.
JAMA Network Open · 202303
Good to know
Other eating patterns can work as well. A 2026 Cochrane review found little or no extra weight loss with intermittent fasting compared with ordinary dietary advice. Its studies covered several fasting patterns and lasted up to a year.
Cochrane · 2026Fasting is unsuitable for some people. Johns Hopkins advises against it for children and teens under 18, during pregnancy or breastfeeding, and for people with an eating-disorder history. A rigid eating window can worsen restrictive or obsessive food behavior.
Johns Hopkins Medicine · 2026Diabetes medicines need a clinician's review. Insulin and sulfonylureas may need adjustment when meal timing changes. Medication and fasting schedules need to be planned and monitored with the prescribing team.
NIDDK · 2024Fatigue and dizziness can occur. Other possible effects include headaches, mood changes, constipation and menstrual changes. Mayo Clinic also flags fasting as a poor fit for people at high risk of bone loss or falls.
Mayo Clinic · 2025Fainting needs medical attention. Even a brief faint should be checked. Incomplete recovery, chest pain or fainting during exercise warrants emergency help.
NHS · 2026Long-term heart safety is unsettled. A 2025 observational study linked an eating span under eight hours with more cardiovascular deaths. It estimated eating hours from two days of recalled intake and cannot show that deliberately following 16:8 caused those deaths.
Chen and colleagues · 202504
From community discussion
Choosing a window around daily life
An evening cutoff can reduce snack decisions. In one discussion, a commenter valued eliminating late-night snacks, and another initially liked having fewer decisions about when to eat. Other replies described the opposite: forbidden hours made them think about food more and overeat when the window opened.
Community · Reddit r/loseitFamily dinners and morning coffee favor different windows. One commenter used noon–8 p.m. to eat with a partner who finished work at 6:30. Another preferred 8 a.m.–4 p.m. for easier morning focus and coffee with cream.
Community · Reddit r/intermittentfastingSome start with a wider window. Some accounts describe starting with 14:10—14 fasting hours and 10 eating hours. They also describe testing noon–8 p.m. or 10 a.m.–6 p.m. for about a week and treating the first weeks as an experiment rather than a permanent commitment.
CommunityHunger and eating enough
Morning hunger sometimes eases after the first week. People describe hunger arriving at their usual breakfast time, then becoming less distracting as the routine settles.
CommunitySkipping breakfast can backfire at lunch. A poster fasting from 8 p.m. to noon described becoming hungry and irritable at work by 10:30, then rushing lunch and possibly overeating. After adding oats, fruit and protein powder at breakfast, they reported smaller lunches and dinners and feeling more balanced.
Community · Reddit r/loseitTraining and enough food can be harder to fit. People describe moving the window so a meal follows training, and checking that enough food and protein fit into the day. Work and shared meals also affect which hours people can keep.
CommunityFollowing the window without weight change
Following 16:8 does not always move the scale. One poster reported little weight change after four consistent months with a 1–9 p.m. window, lunch, a protein-bar snack and dinner. They were not tracking intake and also described medication use and sluggishness.
Community · Reddit r/intermittentfastingReferences for this topic
Sources and context
What Can You Tell Your Patients About Intermittent Fasting and Type 2 Diabetes? ↗
- id
- self-guide-if-niddk — What Can You Tell Your Patients About Intermittent Fasting and Type 2 Diabetes?
- platform
- NIDDK
- role
- Official context
- accessed On
- 2026-09-24
- locator
- Q&A answers on what intermittent fasting is, the noon-to-8 p.m. example, calorie-free drinks, the 12-month comparison, ketones, adherence, and diabetes medicines
- scope
- Defines time-restricted eating versus alternate-day fasting, names the noon-to-8 p.m. fast with water or black coffee or tea, and reports study findings the researcher describes, including medication adjustment for insulin and sulfonylureas.
- limitations
- The page is an expert interview, not a guideline with a visible publication date. It does not prove a personal weight change, and it does not give a meal plan inside the window.
- slugs
- intermittent-fasting
- fasted-training
Intermittent fasting: What are the benefits? ↗
- id
- self-guide-if-mayo — Intermittent fasting: What are the benefits?
- platform
- Mayo Clinic
- role
- Professional context
- accessed On
- 2026-09-24
- locator
- Time-restricted eating, Health effects of intermittent fasting, and Intermittent fasting is not for everyone
- scope
- Dated March 8, 2025. Describes fasts up to 16 hours and shorter fasts, says long-term effects are unclear, notes some evidence on heart risk for a 16-hour and 8-hour cycle, and lists groups for whom the pattern may be a poor fit.
- limitations
- This is a clinic explainer, not a trial. The heart-risk sentence is described as some evidence, not a measured personal risk. It does not set a required eating window.
- slugs
- intermittent-fasting
- fasted-training
What Is Intermittent Fasting? ↗
- id
- self25b2-intermittent-fasting-cleveland-2026 — What Is Intermittent Fasting?
- platform
- Cleveland Clinic
- role
- Professional context
- accessed On
- 2026-09-27
- published Or Updated
- 2026-01-26
- locator
- The 16/8 or 14/10 method; other schedules; Tips when starting intermittent fasting.
- scope
- Overview, overnight example, distinct fasting patterns and calorie-free drinks.
- limitations
- Dietitian explainer; its broad benefit list, sweetener claims and electrolyte suggestions are not adopted.
- slugs
- intermittent-fasting
Intermittent Fasting: What Is It, And How Does It Work? ↗
- id
- self25b2-intermittent-fasting-hopkins-2026 — Intermittent Fasting: What Is It, And How Does It Work?
- platform
- Johns Hopkins Medicine
- role
- Professional context
- accessed On
- 2026-09-27
- published Or Updated
- 2026-04-07
- locator
- What can I eat while intermittent fasting?; Who shouldn't try intermittent fasting?
- scope
- Food quality, compensation through larger meals, and excluded groups.
- limitations
- Expert explainer; mixed animal/human benefit list and disease-reversal language are not adopted.
- slugs
- intermittent-fasting
What Can You Tell Your Patients About Intermittent Fasting and Type 2 Diabetes? ↗
- id
- self25b2-intermittent-fasting-niddk-2024 — What Can You Tell Your Patients About Intermittent Fasting and Type 2 Diabetes?
- platform
- NIDDK
- role
- Official context
- accessed On
- 2026-09-27
- published Or Updated
- 2024-05-01
- locator
- Questions on definition, research, benefits and clinical advice; web extraction lines 122–157.
- scope
- Researcher-reported weight findings and medication oversight.
- limitations
- Expert interview, not the underlying trial; no personal outcome predicted.
- slugs
- intermittent-fasting
Effect of Time-Restricted Eating on Weight Loss in Adults With Type 2 Diabetes: A Randomized Clinical Trial ↗
- id
- self25b2-intermittent-fasting-jama-diabetes-2023 — Effect of Time-Restricted Eating on Weight Loss in Adults With Type 2 Diabetes: A Randomized Clinical Trial
- platform
- JAMA Network Open
- role
- Professional context
- accessed On
- 2026-09-27
- published Or Updated
- 2023-10-27
- locator
- Abstract; Intervention; Medication Management; Blood Glucose Level Monitoring; Conclusion.
- scope
- A1C findings with supervised eight-hour TRE in type 2 diabetes and obesity.
- limitations
- 75 adults, six months, one center; does not establish unsupervised safety or universal benefit.
- slugs
- intermittent-fasting
Intermittent fasting, traditional dietary advice or no treatment: which works better to help adults living with overweight or obesity lose weight? ↗
- id
- self25b2-intermittent-fasting-cochrane-2026 — Intermittent fasting, traditional dietary advice or no treatment: which works better to help adults living with overweight or obesity lose weight?
- platform
- Cochrane
- role
- Professional context
- accessed On
- 2026-09-27
- published Or Updated
- 2026-02-16
- locator
- Key messages; What did we find?; Authors' conclusions; Published.
- scope
- Comparative weight-loss limit and follow-up duration.
- limitations
- Multiple IF patterns; evidence through November 5, 2024. Most outcomes have low or very low certainty.
- slugs
- intermittent-fasting
Intermittent fasting: What are the benefits? ↗
- id
- self25b2-intermittent-fasting-mayo-2025 — Intermittent fasting: What are the benefits?
- platform
- Mayo Clinic
- role
- Professional context
- accessed On
- 2026-09-27
- published Or Updated
- 2025-03-08
- locator
- Health effects of intermittent fasting; Intermittent fasting is not for everyone.
- scope
- Side effects and bone-loss/fall cautions.
- limitations
- Clinic summary. Its heart-risk sentence is replaced by the inspected 2025 original observational abstract and its limitations.
- slugs
- intermittent-fasting
Fainting ↗
- id
- self25b2-intermittent-fasting-nhs-fainting-2026 — Fainting
- platform
- NHS
- role
- Official context
- accessed On
- 2026-09-27
- published Or Updated
- 2026-08-17
- locator
- When and where to get medical help; Immediate action required; Page last reviewed.
- scope
- Assessment after fainting and selected emergency warning signs.
- limitations
- General symptom guidance; does not attribute a faint to fasting or diagnose its cause.
- slugs
- intermittent-fasting
Association of eating duration less than 8 h with all-cause, cardiovascular, and cancer mortality ↗
- id
- self25b2-intermittent-fasting-chen-mortality-2025 — Association of eating duration less than 8 h with all-cause, cardiovascular, and cancer mortality
- platform
- PubMed / Diabetes & Metabolic Syndrome
- role
- Professional context
- accessed On
- 2026-09-27
- published Or Updated
- 2025-08-22
- locator
- Original article abstract, Methods through Conclusions; Epub date. DOI: 10.1016/j.dsx.2025.103278.
- scope
- Observational cardiovascular association, two dietary recalls and unresolved confounding.
- limitations
- Abstract inspected; publisher full text unavailable. Under-eight-hour category is not a randomized 16:8 regimen. Journal issue is July 2025; online date is August 22.
- slugs
- intermittent-fasting
Is intermittent fasting unhelpful for some people? ↗
- id
- self25b2-intermittent-fasting-reddit-restriction-1dbdpkj — Is intermittent fasting unhelpful for some people?
- platform
- Reddit r/loseit
- role
- Community discussion
- accessed On
- 2026-09-27
- locator
- Opening post; deleted-user replies on snacking and food fixation, lines 148–175; libbyrocks on decision relief, lines 533–538; adjoining mixed reports.
- scope
- Reduced eating decisions versus increased food preoccupation and compensatory eating.
- limitations
- Mixed first-person reports; some usernames deleted but comments remain visible. No prevalence or causal diagnosis. No exact date inferred from relative timestamps.
- slugs
- intermittent-fasting
16:8 is basically skip breakfast and don't eat late, right? ↗
- id
- self25b2-intermittent-fasting-reddit-windows-1ccgi52 — 16:8 is basically skip breakfast and don't eat late, right?
- platform
- Reddit r/intermittentfasting
- role
- Community discussion
- accessed On
- 2026-09-27
- locator
- spookyboi13 reply on partner's 6:30 finish; Effective-Fix-6895 replies on 8 a.m.–4 p.m., focus and cream; adjoining replies, extraction lines 297–356.
- scope
- Different schedules around shared dinner and a preferred morning drink.
- limitations
- Self-selected anecdotes. Claims about next-day fat loss and better metabolism are not adopted. Only relative dates exposed on the opened page.
- slugs
- intermittent-fasting
Does having breakfast help you? Also some thoughts on fasting ↗
- id
- self25b2-intermittent-fasting-reddit-breakfast-1k0nk16 — Does having breakfast help you? Also some thoughts on fasting
- platform
- Reddit r/loseit
- role
- Community discussion
- accessed On
- 2026-09-27
- locator
- rainrain-throwaway6 opening post, follow-up on work/parenthood, and replies about hunger and breakfast.
- scope
- Workday irritability, possible lunchtime compensation, and reported change after breakfast.
- limitations
- Personal observations, not measured intake or a controlled comparison. Opened page exposes relative dates; no exact date asserted.
- slugs
- intermittent-fasting
Doing 16:8 for months (and years before), still no weight loss. Looking for honest feedback ↗
- id
- self25b2-intermittent-fasting-reddit-nonresponse-1q5qe6s — Doing 16:8 for months (and years before), still no weight loss. Looking for honest feedback
- platform
- Reddit r/intermittentfasting
- role
- Community discussion
- accessed On
- 2026-09-27
- locator
- existential_otter22 opening routine and medication context; follow-up on sluggishness; replies on tracking, medications and longer fasts.
- scope
- Nonresponse despite reported adherence and the uncertainty of explanations offered in replies.
- limitations
- No verified intake, weight series or clinical assessment. Do not diagnose overeating, medication effects or metabolic damage; do not promote escalation to longer fasts. Exact date not used.
- slugs
- intermittent-fasting
Keep this topic in view
Preserved original record
Earlier public profile and reader notes are preserved separately from the current article. They may contain superseded wording and are not newly checked material.
Read the full original profile
- slug
- intermittent-fasting
- name
- Intermittent fasting / 16:8
- aliases
- 16:8
- time restricted eating
- TRE
- IF
- eating window
- fasting window
- family
- fuel
- heat
- high
- talk
- Lots of talk
- most Discussed
- false
- first Line
- Intermittent fasting / 16:8 means keeping daily meals inside a chosen clock window such as sixteen hours off and eight hours on.
- why Line
- A smaller eating window feels simpler to some people and awkward to others. Hunger at the old meal time, social dinners and fitting enough food around training often determine whether the schedule is sustainable.
- feel Words
- 16:8
- time restricted eating
- TRE
- IF
- eating window
- fasting window
- common Picture
- lead
- The meal window can move
- why
- Skipping breakfast and finishing dinner earlier are two different versions described. [community]
- lead
- Drinks complicate the label
- why
- Water, black coffee and tea appear in fasting logs; cream and other additions change what was consumed. [community]
- watch For
- An eating-disorder history, pregnancy or diabetes medicines can change whether fasting is appropriate. Fainting needs assessment, not a stricter eating window.
- what People Say
- The job: eat inside a daily window and stop grazing at night. [community]
- r/intermittentfasting is 16:8 screenshots and ‘does coffee break it.’ [community]
- Skeptics: calories still count; the window is an appetite tool. [community]
- Not a medical fast. Diabetes meds and fainting are a clinician. [community]
- how People Run It
- Pick 12–8 or 10–6 and keep it a week before you judge. [community]
- Water, black coffee, unsweetened tea outside the window is the usual rule. [community]
- amounts People Use
- 16 hours ‘off,’ 8 hours on is the named split. [community]
- Some run 14:10 first. [community]
- how People Keep It
- A calendar window beats a perfect day. [community]
- how It Feels
- Week one: hungry at the old breakfast hour, then it often quiets. [community]
- how Long People Run It
- Weeks as an experiment, not a forever vow on night three. [community]
- deep Dive
- Food still matters within the window: Community accounts discuss total energy and protein intake alongside the chosen eating hours. A schedule someone can keep does not by itself establish that they are eating enough or meeting their nutrition needs. [community]
- The same window can make two different days: Skipping breakfast and finishing dinner early both shorten eating time, but affect work, training and shared meals differently. The accounts describe hunger at a familiar meal time, coffee rules and using a wider window first. They do not show that everyone adapts on the same schedule or eats enough automatically inside a shorter window. [community]
- What to notice in a report: The eating window describes timing, not the quality or quantity of the food inside it. A useful account says whether meals, appetite, social life or training changed, and whether the person found the routine easier to keep. Disordered eating, pregnancy and diabetes medicines can change whether fasting is appropriate; a forum eating window is not a prescription. [community]
- watch For Long
- Disordered-eating history, pregnancy, insulin: clinician. [community]
- related
- protein-breakfast
- finish-dinner-early
- protein-target
- last-coffee
- research Pointer
- play Pointer
- —
- forums
- r/intermittentfasting
- r/loseit
- sources
- r/intermittentfasting 16:8 logs
- 2026 TRE vs calorie-count fights
- TRE vs calorie-count 2026 fights
- disclaimer
- Community talk. May contain inaccuracies. Not medical or health advice. No result or safety is promised.
- quick Answer History
- field
- communityPicture
- rows
- Community notes describe skipping breakfast or late dinner, drinking unsweetened coffee outside the window, and arguing whether calories still explain the result. It is a kitchen clock, not a compound card.
- field
- deepDive
- rows
- A clock, not a religion: The object is the eating window people can actually keep. Calories and protein still show up in the honest threads. [community]
- field
- commonPicture
- rows
- lead
- A window, not a food list
- why
- 16:8 is hours. The plate inside the window is a different fight. [community]
- lead
- Coffee still counts as ‘fasting’ in most logs
- why
- Black coffee / tea / water. Cream wars start here. [community]
- lead
- Skip breakfast or skip late dinner
- why
- Two common clocks. [community]
- lead
- Not a compound
- why
- No vial. Kitchen clock. [community]
- field
- firstLine
- rows
- 16:8 is an eating window, not a compound — skip breakfast or skip late dinner and keep the hours the same.
- field
- whyLine
- rows
- 16:8 is an eating window, not a compound — skip breakfast or skip late dinner and keep the hours the same.
- field
- watchFor
- rows
- History of disordered eating, pregnancy, diabetes meds, fainting. This is a kitchen clock, not a protocol or a Research vial.
Read the preserved reader notes
- picture Clarifications
- definition
- Intermittent fasting / 16:8 means keeping daily meals inside a chosen clock window such as sixteen hours off and eight hours on.
- community Picture
- A smaller eating window feels simpler to some people and awkward to others. Hunger at the old meal time, social dinners and fitting enough food around training often determine whether the schedule is sustainable.
- additions
- guide
- what
- The moving part is which hours contain food. An NIDDK Q&A accessed September 24, 2026, describes time-restricted eating as the form studied most, often on a noon-to-8 p.m. clock so dinner remains. From 8 p.m. until the next noon, that page keeps the fast to water or a calorie-free drink such as black coffee or tea. Cream, milk, and sugar are calories, so they open the eating window.
- This is not alternate-day fasting. The same Q&A describes that other pattern as a day of water, or about 500 to 600 calories, then a day of untracked eating. Mayo Clinic's page dated March 8, 2025, treats intermittent fasting as a time limit: ordinary eating, then very few or no calories, including a fast of up to 16 hours and shorter fasts. An early window and a late window are different days.
- On the NIDDK page, the researcher reads the effect as eating less inside a six- to eight-hour window, about 500 calories in that description, not as a meaningful ketone rise after 16 hours. The clock does not measure protein or portions.
- how
- Write the first bite and the last bite before the week starts. Noon to 8 p.m. is the clock the NIDDK Q&A says is often kept because dinner is the meal people do not want to skip. Eating earlier and fasting through the evening is the other pattern on Mayo's page. Keep one clock for the trial. A window that moves every day is a different test.
- Outside those hours, drink water. Black coffee or plain tea stays in the fast only when it has no calories, which is the NIDDK line. Cream, syrup, or milk is the first bite. Start the eating hours there. Inside the window, eat meals instead of a long graze. The Q&A says the studied pattern does not require a calorie log during those hours. The meals still have to be enough food for the day.
- If a workout sits near the edge, put the meal after it inside the window, or shift the window so that meal fits. Do not change the menu, the training, and the clock in the same week if the question is whether the clock is tolerable. A kept week uses the same hours, calorie-free drinks outside them, and ordinary meals inside them.
- The NIDDK Q&A reports that people in those studies stayed inside a six- to eight-hour window on about 6 of 7 days. Build the clock around the meal that will not move. Hunger at the old breakfast hour is part of the first days of a late window. How long that lasts, and which drinks people argue about, is in the community notes.
- understand
- The pattern is built to drop night eating and the tracking chore together. In the NIDDK Q&A, a 12-month comparison found about 5 percent weight loss with time-restricted eating and about the same with daily calorie restriction. The researcher's reading is that people eat less because the time is shorter. Mayo's March 8, 2025 page says the long-term picture is not clear, and that some studies find plain calorie limiting may match the benefit.
- Mayo also says some evidence suggests a 16-hour fast with an 8-hour eating period may raise heart-disease risk compared with other cycles. That keeps this split from being a settled upgrade over a wider window. The common miss is an empty morning plus meals inside the window that are too small to cover the day, or a clock that never stays put.
- Mayo's page says the pattern may be a poor fit with an eating disorder, in pregnancy or while breastfeeding, or with a high risk of bone loss and falls. It can bring fatigue, dizziness, and trouble with diabetes management. The NIDDK Q&A says pregnancy has not been studied there, and that insulin or a sulfonylurea needs a clinician's adjustment when fasting hours are added. Fainting is a clinician visit, not a tighter clock.
- sources
End of Intermittent fasting / 16:8