- Fasting works by making it easier to eat less, not through special metabolic effects.
- Studies show similar fat loss to daily calorie restriction when calories match.
- Protein and strength training still matter, and are harder to fit into short windows.
- Get advice first if you are pregnant, have diabetes or have an eating disorder history.
What intermittent fasting is
Intermittent fasting (IF) is a way of structuring when you eat rather than what you eat. There are several common versions:
- 16:8 (time-restricted eating): eat within an eight-hour window, for example 12pm to 8pm, and fast for the other 16 hours.
- 14:10: a gentler version with a ten-hour eating window, which many people find easier to keep up.
- 5:2: eat normally five days a week and eat much less, often around 500 to 600 kcal, on two non-consecutive days.
- Alternate day fasting: alternating normal days with very low calorie days. Hard to stick to for most people.
Most people who try IF start with 16:8 or 14:10, often simply by skipping breakfast and making lunch their first meal of the day. Fasting itself is nothing new; people have fasted for religious, cultural and practical reasons for thousands of years. What is new is marketing it as a fat loss method.
Does it work for fat loss?
Yes, but for a plain reason. Shrinking the window in which you eat usually means fewer meals and snacks, which reduces total calories. If you eat the same amount in eight hours as you would have in fourteen, the result is the same.
Studies comparing intermittent fasting with ordinary daily calorie restriction generally find similar weight and fat loss when calories are matched. Claims that fasting resets your hormones or switches on fat burning beyond the normal effects of a deficit are not well supported in everyday life.
That does not make it pointless. If a fasting schedule makes eating less easier for you, it is a perfectly valid tool. If it makes you ravenous, grumpy and prone to overeating at night, it is the wrong tool for you.
Some people also find the structure helps psychologically. A clear rule, such as nothing after 8pm, can be easier to follow than trying to moderate snacking all evening.
Who it suits
- People who are not hungry in the morning and have always found breakfast a chore.
- People who prefer two or three larger, satisfying meals to lots of small ones.
- Busy people who like fewer food decisions in the day.
- People who snack a lot in the evening and want a firm cut-off time.
It tends to suit people less if they train early and feel weak without food, if they get very hungry and irritable when they skip meals, or if their family routine is built around breakfast together. None of those people are doing anything wrong by eating in the morning.
Who should avoid it or get advice first
Fasting is not safe or suitable for everyone. Avoid it, or speak to your GP first, if you:
- Are pregnant, breastfeeding or trying to conceive.
- Have a current or past eating disorder.
- Have diabetes, especially if you take insulin or other medicines that lower blood sugar.
- Take medication that needs to be taken with food.
- Are under 18.
- Have any other condition affecting blood pressure or blood sugar.
Older adults who already struggle to eat enough protein may also find that fasting makes it harder.
If fasting makes you preoccupied with food, anxious about eating or prone to bingeing, stop. Our guide on emotional eating may help.
Fitting it around training
Training and fasting can work together, but a little planning helps. Strength and high-intensity sessions tend to go better with some food in the tank, so many people schedule their eating window around their training. If you train in the evening, a 12pm to 8pm window works well. If you train at 6am, you might shift the window earlier, such as 7am to 3pm, or simply have a small snack before training.
Easy morning cardio before your first meal is fine for most people, as our guide to fasted cardio explains. Hard conditioning or HYROX training on an empty stomach is usually a worse idea. After training, aim to eat a meal with protein within a couple of hours, so avoid finishing a hard evening session just as your window closes.
Protein in a shorter window
The biggest practical downside of IF for people who lift is protein. Hitting 1.6 to 2.2 g per kg of body weight a day is harder in two meals than in four. A 90 kg person aiming for 150 g needs around 50 to 75 g per meal across two or three meals.
The solution is to make every meal protein-heavy, add a protein-rich snack within the window and use a shake if needed. Our guide to protein for fat loss has practical ideas.
For example, a first meal of three eggs with Greek style yoghurt and fruit (around 35 g of protein), a mid-afternoon tuna wrap (around 30 g) and an evening meal built on 200 g of raw chicken breast or lean mince (around 40 to 45 g) gets you to roughly 110 g before any snacks or shakes.
Ramadan and religious fasting
Many people in Greater Manchester fast during Ramadan, which is a different situation from choosing IF for fat loss. Eating times are fixed by dawn and sunset, water is not allowed during the fast, and sleep is often disrupted. Our guide on training and nutrition during Ramadan covers how to adjust training, hydration and meals during the month.
Whatever pattern you follow, the principles do not change: a moderate deficit, enough protein, strength training and sleep. If you want help deciding whether IF suits your routine, Lycan Strength offers nutrition and accountability coaching alongside its classes.
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Questions
Is intermittent fasting better than calorie counting?
Not for fat loss itself. Studies show similar results when calories match. It is better only if you find it easier to stick to.
Can I drink coffee while fasting?
Black coffee, tea and water are generally fine during a fast. A splash of milk makes little practical difference for fat loss.
Will intermittent fasting make me lose muscle?
Not if you eat enough protein and keep strength training. The risk rises if protein is low or the deficit is too large.
Is 16:8 fasting good for women?
Many women do well with it, but some find it affects sleep, mood or their cycle. A gentler 14:10 window is a good place to start.
General guidance for healthy adults. If you have a medical condition, injury or are pregnant, check with a health professional before changing your training or diet.
