Will intermittent fasting help me lose weight faster than other diets?

Not typically. Studies comparing IF to standard calorie-controlled diets usually show similar weight loss when total calories are matched. IF may simply make it easier for some people to eat less overall.

Can I drink coffee or tea during a fasting window?

Black coffee and plain tea (without sugar or milk) contain negligible calories and are generally fine during fasting periods for most healthy adults, though check with a doctor if you have any relevant health conditions.

Is intermittent fasting safe for everyone?

No. It isn't recommended for pregnant or breastfeeding people, those with a history of disordered eating, people on certain diabetes medications, or anyone with a medical condition without professional guidance.

Do I still need to watch calories and macros while doing IF?

Yes. Fasting controls timing, not nutritional quality or quantity. Tracking your calories and macros during your eating window helps ensure you're meeting your nutritional needs and actual goals.

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Nutrition guide

Intermittent fasting: a beginner's guide

Intermittent fasting (IF) has become one of the most talked-about approaches to eating, with claims ranging from weight loss to improved metabolic health. Stripped back, it's simply a way of structuring when you eat rather than what you eat. This guide explains the main methods, what the evidence actually shows, and how to try it safely if it appeals to you.

By the Nutari team · Reviewed for general accuracy · Updated 2026-09-20

Key takeaways

Intermittent fasting restricts the timing of meals, not necessarily what or how much you eat overall.
Most of its benefits for weight management come from eating fewer calories overall, not from any special metabolic effect of fasting itself.
Evidence for IF beyond calorie control is mixed and often shows similar results to standard calorie-controlled diets.
It isn't suitable for everyone, including people who are pregnant, have a history of disordered eating, or take medication for diabetes.
Tracking your food and calories during your eating window can help you see whether IF is actually working for you.

What is intermittent fasting?

Intermittent fasting refers to eating patterns that cycle between periods of eating and periods of little or no food intake. Unlike traditional diets that focus on what you eat, IF focuses on when you eat.

It's not a single diet but a family of approaches. Some people use it to simplify meal planning, others hope it will support weight loss or metabolic health. The scientific picture is more nuanced than much of the popular messaging suggests, so it's worth understanding the methods and the evidence before diving in.

Common intermittent fasting methods

There are several popular ways to structure intermittent fasting:

16:8 (time-restricted eating): You eat within an 8-hour window each day (for example, midday to 8pm) and fast for the remaining 16 hours, which mostly includes sleep.
5:2: You eat normally five days a week and significantly reduce calorie intake (often to around 500-600 calories) on two non-consecutive days.
One Meal a Day (OMAD): All of a day's calories are consumed in a single meal, with roughly 23 hours of fasting. This is a more extreme approach and generally harder to sustain or meet nutritional needs with.

Other variations exist, such as alternate-day fasting, but the principle is the same: compress your eating into a shorter window or fewer days.

How intermittent fasting can help - and its limits

For many people, IF's main benefit is indirect: by shortening the eating window, it becomes harder to fit in as much food, which naturally reduces total calorie intake. Since a calorie deficit is what drives weight loss, this is often why people see results with IF - not because fasting itself has a unique fat-burning effect.

Research comparing IF to standard daily calorie restriction generally finds similar outcomes for weight loss when total calories are matched. Some studies suggest possible benefits for blood sugar control or blood lipids, but results are inconsistent, often short-term, and vary between individuals.

In short, intermittent fasting isn't magic, and it isn't inherently superior to other calorie-controlled approaches. It's simply one tool among several, and it suits some lifestyles and appetites better than others.

Who should be cautious or avoid intermittent fasting

Intermittent fasting isn't appropriate for everyone. You should speak to a doctor or dietitian before trying it if you:

Are pregnant or breastfeeding
Have a current or past history of disordered eating or an eating disorder
Have diabetes and take insulin or other glucose-lowering medication, due to the risk of dangerously low blood sugar
Have a diagnosed medical condition, are underweight, or are taking regular medication that requires food
Are a child, teenager, or otherwise still growing

If you notice fasting triggers preoccupation with food, irritability, or disrupted eating patterns, it's worth stepping back and seeking guidance rather than pushing through.

How to start intermittent fasting safely

If you'd like to try IF and it's appropriate for you, a gradual, sensible approach works best:

Start with a milder pattern, such as 12:12 or 14:10, before attempting 16:8 or more restrictive schedules.
Focus on nutrient-dense, balanced meals within your eating window rather than using the fast as an excuse to eat less healthily afterwards.
Stay well hydrated during fasting periods with water, and unsweetened tea or coffee if tolerated.
Track what you eat during your eating window using an app - this helps you check you're still meeting your calorie and protein needs rather than accidentally under- or overeating.
Listen to your body. Persistent fatigue, dizziness, or irritability are signs to adjust or stop.

Give any new pattern a few weeks before judging how it fits your life, energy levels, and goals.

Is intermittent fasting right for you?

IF can be a useful structure for people who find it easier to manage fewer, larger meals rather than grazing throughout the day. For others, it can feel restrictive or lead to overeating during the eating window, which cancels out any calorie benefit.

There's no single 'best' way to eat for everyone. The most sustainable approach is usually the one that fits your routine, preferences, and health needs - whether that includes fasting windows or not. If in doubt, a registered dietitian can help you weigh up whether IF suits your circumstances.

FAQ

Will intermittent fasting help me lose weight faster than other diets?: Not typically. Studies comparing IF to standard calorie-controlled diets usually show similar weight loss when total calories are matched. IF may simply make it easier for some people to eat less overall.
Can I drink coffee or tea during a fasting window?: Black coffee and plain tea (without sugar or milk) contain negligible calories and are generally fine during fasting periods for most healthy adults, though check with a doctor if you have any relevant health conditions.
Is intermittent fasting safe for everyone?: No. It isn't recommended for pregnant or breastfeeding people, those with a history of disordered eating, people on certain diabetes medications, or anyone with a medical condition without professional guidance.
Do I still need to watch calories and macros while doing IF?: Yes. Fasting controls timing, not nutritional quality or quantity. Tracking your calories and macros during your eating window helps ensure you're meeting your nutritional needs and actual goals.

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This guide is general educational information, not medical or dietetic advice. Everyone's needs differ — talk to a doctor or registered dietitian before making big changes, especially with a health condition, pregnancy, or a history of disordered eating.

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