Quick answer
- A marathon training diet is not one menu, it is four day-types repeated: rest days at roughly 3 to 4 g of carbohydrate per kilogram of body weight, easy days at 4 to 6 g/kg, quality days at 6 to 8 g/kg, and long-run days at 7 to 9 g/kg including fuel taken during the run.
- Protein stays constant at 1.6 to 2.0 g per kg every day, split into four feedings of 25 to 40 g.
- The diet then shifts across the block: base phase builds habits, build phase adds in-run fuelling practice, peak phase demands the highest intakes, and the taper reduces calories only slightly while keeping carbohydrate high.
5 key facts
- Carbohydrate should move with the session; protein and vegetables should not move at all.
- The most common marathon-training nutrition failure is holding food constant while training volume doubles.
- Every long run is a rehearsal for race-day fuelling, so practise the products and the timing you intend to race with.
- Taper weeks reduce training by 40 to 60 percent, but cutting food by the same proportion arrives at the start line under-fuelled.
- Four repeatable day templates and one grocery list solve more of this than any 16-week prescriptive menu.
Search for a marathon training diet and you will be handed a 16-week menu with a numbered breakfast for every day. Nobody has ever followed one of those to week three. Real marathon training moves: a session gets pushed to Wednesday, the long run gets shortened because of weather, a work trip eats a Tuesday. A menu breaks. A system does not.
So this is a system. Four day templates, one set of targets, and a description of how the whole thing shifts as the block progresses. Learn the four days and you can build any week of any plan.
The two rules underneath everything
Rule one: carbohydrate follows training. It is the fuel that runs out, so it should be highest on the days that use the most of it and lowest on the days that do not.
Rule two: protein does not follow training. Repair demand is roughly constant, and the days you are rebuilding hardest are often the days after the hardest session, not the day of it. Hold protein at 1.6 to 2.0 g per kilogram of body weight every single day, including rest days, split across four feedings.
| Day type | Carbohydrate | Protein | Fat |
|---|---|---|---|
| Rest day | 3 to 4 g/kg | 1.6 to 2.0 g/kg | Fill the remainder |
| Easy run day | 4 to 6 g/kg | 1.6 to 2.0 g/kg | Fill the remainder |
| Quality day (intervals, tempo) | 6 to 8 g/kg | 1.6 to 2.0 g/kg | Lower around the session |
| Long run day | 7 to 9 g/kg | 1.6 to 2.0 g/kg | Lower before, normal after |
For a 70 kg runner those carbohydrate targets are roughly 210 to 280 g on a rest day, 280 to 420 g on an easy day, 420 to 560 g on a quality day, and 490 to 630 g on a long-run day. That is a swing of more than 400 g across the week, which is exactly why a single fixed menu cannot work.
Day template 1: easy run day
Breakfast
Oats with milk, banana, honey; coffee
Approx. carbs / protein75 g / 20 g
Lunch
Chicken and rice bowl with vegetables, yoghurt
Approx. carbs / protein80 g / 45 g
Afternoon
Apple and a handful of nuts
Approx. carbs / protein25 g / 5 g
Run
45 to 60 min easy, water only
Approx. carbs / protein0 g
Dinner
Salmon, potatoes, greens
Approx. carbs / protein60 g / 40 g
Evening
Greek yoghurt with berries
Approx. carbs / protein20 g / 20 g
| Meal | Example | Approx. carbs / protein |
|---|---|---|
| Breakfast | Oats with milk, banana, honey; coffee | 75 g / 20 g |
| Lunch | Chicken and rice bowl with vegetables, yoghurt | 80 g / 45 g |
| Afternoon | Apple and a handful of nuts | 25 g / 5 g |
| Run | 45 to 60 min easy, water only | 0 g |
| Dinner | Salmon, potatoes, greens | 60 g / 40 g |
| Evening | Greek yoghurt with berries | 20 g / 20 g |
This is a normal day of food. That is the point. Easy days do not need special handling, and treating every run as an occasion requiring intervention is how runners end up over-eating on the days that matter least.
Day template 2: quality session day
07:00
Bagel with jam, banana, coffee
Approx. carbs / protein90 g / 12 g
10:00
Yoghurt, granola, orange juice
Approx. carbs / protein65 g / 20 g
12:30
Pasta with tomato sauce and chicken, bread
Approx. carbs / protein110 g / 45 g
16:30
Pre-session: two slices of toast with honey
Approx. carbs / protein45 g / 6 g
18:00
Intervals; sports drink during if over 75 minutes
Approx. carbs / protein20 g
19:30
Rice, beef or tofu stir fry, plus a glass of milk
Approx. carbs / protein100 g / 45 g
21:30
Cereal or rice pudding
Approx. carbs / protein45 g / 10 g
| Time | Meal | Approx. carbs / protein |
|---|---|---|
| 07:00 | Bagel with jam, banana, coffee | 90 g / 12 g |
| 10:00 | Yoghurt, granola, orange juice | 65 g / 20 g |
| 12:30 | Pasta with tomato sauce and chicken, bread | 110 g / 45 g |
| 16:30 | Pre-session: two slices of toast with honey | 45 g / 6 g |
| 18:00 | Intervals; sports drink during if over 75 minutes | 20 g |
| 19:30 | Rice, beef or tofu stir fry, plus a glass of milk | 100 g / 45 g |
| 21:30 | Cereal or rice pudding | 45 g / 10 g |
Notice the low-fat pre-session snack two to three hours out, and the fact that the largest carbohydrate meals sit on either side of the session. That placement matters more than the total. The same 500 g eaten as one enormous dinner would leave you flat during the workout and stuffed at bedtime.
Day template 3: long run day
06:30
Two slices white toast with honey, banana, coffee
Approx. carbs / protein80 g / 8 g
08:00 to 10:30
Long run with 60 g carbohydrate per hour
Approx. carbs / protein150 g
10:45
Recovery: shake with 60 g carbs plus 25 g protein
Approx. carbs / protein60 g / 25 g
12:30
Big lunch: rice bowl, eggs, avocado, juice
Approx. carbs / protein110 g / 35 g
16:00
Sandwich and fruit
Approx. carbs / protein60 g / 15 g
19:00
Pasta, chicken, vegetables, bread
Approx. carbs / protein120 g / 45 g
21:30
Yoghurt and honey
Approx. carbs / protein30 g / 18 g
| Time | Meal | Approx. carbs / protein |
|---|---|---|
| 06:30 | Two slices white toast with honey, banana, coffee | 80 g / 8 g |
| 08:00 to 10:30 | Long run with 60 g carbohydrate per hour | 150 g |
| 10:45 | Recovery: shake with 60 g carbs plus 25 g protein | 60 g / 25 g |
| 12:30 | Big lunch: rice bowl, eggs, avocado, juice | 110 g / 35 g |
| 16:00 | Sandwich and fruit | 60 g / 15 g |
| 19:00 | Pasta, chicken, vegetables, bread | 120 g / 45 g |
| 21:30 | Yoghurt and honey | 30 g / 18 g |
The 150 g consumed during the run is not a bonus, it is a core part of the day’s total, and it is also the single most important rehearsal you do all week. Whatever you intend to use on race day should be in your hand on these mornings: the same gels, the same drink, the same intervals between them.
Day template 4: rest day
Breakfast
Eggs on toast, fruit
Approx. carbs / protein40 g / 28 g
Lunch
Large salad with chicken, quinoa, olive oil
Approx. carbs / protein45 g / 45 g
Snack
Cottage cheese and fruit
Approx. carbs / protein20 g / 20 g
Dinner
Fish, sweet potato, vegetables
Approx. carbs / protein55 g / 40 g
Evening
Small yoghurt
Approx. carbs / protein15 g / 15 g
| Meal | Example | Approx. carbs / protein |
|---|---|---|
| Breakfast | Eggs on toast, fruit | 40 g / 28 g |
| Lunch | Large salad with chicken, quinoa, olive oil | 45 g / 45 g |
| Snack | Cottage cheese and fruit | 20 g / 20 g |
| Dinner | Fish, sweet potato, vegetables | 55 g / 40 g |
| Evening | Small yoghurt | 15 g / 15 g |
Carbohydrate is down to about 175 g, protein has not moved, and no meal has been skipped. That is what a rest day should look like. If your rest day involves eating nothing until 2 p.m. to compensate for yesterday, you are undoing yesterday.
How the diet changes across the block
Base, weeks 1 to 6
TrainingVolume building, mostly easy
Nutrition priorityEstablish habits: protein at every meal, carbohydrate that scales with the day. Do not add fuelling complexity yet
Build, weeks 7 to 12
TrainingQuality sessions plus long runs
Nutrition priorityStart systematic in-run fuelling. Move from 30 to 60 g per hour over several weeks. Test products
Peak, weeks 13 to 16
TrainingLongest runs, marathon-pace work
Nutrition priorityHighest intakes of the whole block. Rehearse race-day breakfast and fuelling exactly
Taper, final 2 to 3 weeks
TrainingVolume drops 40 to 60 percent
Nutrition priorityReduce calories only slightly. Keep carbohydrate high; the goal is full glycogen, not a lean week
Race week
TrainingMinimal training
Nutrition priorityCarbohydrate load to 8 to 12 g/kg over the final 24 to 48 hours; reduce fibre; nothing new
| Phase | Training | Nutrition priority |
|---|---|---|
| Base, weeks 1 to 6 | Volume building, mostly easy | Establish habits: protein at every meal, carbohydrate that scales with the day. Do not add fuelling complexity yet |
| Build, weeks 7 to 12 | Quality sessions plus long runs | Start systematic in-run fuelling. Move from 30 to 60 g per hour over several weeks. Test products |
| Peak, weeks 13 to 16 | Longest runs, marathon-pace work | Highest intakes of the whole block. Rehearse race-day breakfast and fuelling exactly |
| Taper, final 2 to 3 weeks | Volume drops 40 to 60 percent | Reduce calories only slightly. Keep carbohydrate high; the goal is full glycogen, not a lean week |
| Race week | Minimal training | Carbohydrate load to 8 to 12 g/kg over the final 24 to 48 hours; reduce fibre; nothing new |
The taper is where the most damage gets done, and it is almost always self-inflicted. Training volume falls, the runner feels sluggish and unearned, and they cut food to compensate. Then they start the marathon with partially filled glycogen stores after four months of work. Feeling heavy and restless in taper week is normal. Eating less to fix it is not.
A grocery list that makes this repeatable
- Carbohydrate base: oats, rice (white and brown), pasta, potatoes, sweet potatoes, bread, bagels, tortillas.
- Fast carbohydrate: bananas, dates, honey, jam, dried fruit, fruit juice, sports drink powder.
- Protein: eggs, Greek yoghurt or skyr, milk, chicken, salmon or tinned fish, lean beef, tofu, lentils, whey or plant protein powder.
- Fats: olive oil, nuts, seeds, avocado, nut butter. Keep these away from the two hours before hard sessions.
- Vegetables and fruit: anything, in quantity, on every day except immediately before long runs and races.
- Training fuel: gels, chews, drink mix. Buy enough to use them weekly rather than saving them for the race.
The batch-cooking pattern that survives marathon training is dull and effective: cook a large pot of rice or pasta and a tray of protein twice a week, keep bananas and bread visible, and never let the house run out of the thing you eat before long runs.
The weight question
Many people start a marathon block hoping to lose weight, and marathon training is a poor tool for it. Appetite rises, the sessions that drive fitness are the ones a deficit damages first, and the risk of low energy availability, illness, and stress fracture climbs. If body composition genuinely matters to you, take a small deficit during the base phase, not during peak weeks or the taper, and never during race week.
The practical compromise: hold energy availability adequate on quality and long-run days, and take any deficit out of rest and easy days. That protects the sessions that make you faster while still moving the needle slowly.
Frequently asked questions
What should I eat while training for a marathon?
Ordinary food in quantities that follow your training. Carbohydrate from 3 to 4 g per kg on rest days up to 7 to 9 g per kg on long-run days, protein steady at 1.6 to 2.0 g per kg across four feedings, and enough fat, fruit and vegetables to keep the diet complete.
How many calories should I eat during marathon training?
It depends on your body size and the week, but expect a swing of 800 to 1,200 kcal between a rest day and a long-run day. Rather than fixing a daily calorie number, set carbohydrate and protein by day type and let energy follow.
Should I eat differently in taper week?
Yes, but less than most people think. Training volume drops sharply, so total energy comes down a little, but carbohydrate should stay high and rise further in the final 24 to 48 hours. The goal of taper eating is full glycogen at the start line.
Can I lose weight while marathon training?
It is possible but rarely advisable during the hardest phases. If you attempt it, hold a small deficit during the base phase, keep quality and long-run days fully fuelled, and stop entirely for the taper and race week.
What should I eat before a long run?
A carbohydrate-focused, low-fat, low-fibre meal of roughly 1 to 2 g of carbohydrate per kg of body weight two to three hours before, then fuel during the run itself at 30 to 60 g per hour, rising toward 60 to 90 g as the block progresses.
Do I need supplements during marathon training?
Rarely. Caffeine has good evidence for race day. Beyond that, protein powder and sports drinks are conveniences, and iron or vitamin D only after a blood test showing a deficiency. Nothing in a tub compensates for eating too little.
Sources
- 1Nutrition for Marathon Running: Consensus StatementInternational Journal of Sport Nutrition and Exercise Metabolism (Burke et al., 2019)Training-phase and race-day carbohydrate recommendations for marathon runners
- 2Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and ACSM: Nutrition and Athletic PerformanceMedicine and Science in Sports and Exercise (Thomas et al., 2016)Daily macronutrient targets and energy availability
- 3IOC Consensus Statement on Relative Energy Deficiency in Sport (RED-S)British Journal of Sports Medicine (Mountjoy et al., 2018)Consequences of under-fuelling during heavy training blocks
- 4Carbohydrates for Training and CompetitionJournal of Sports Sciences (Burke et al., 2011)Day-to-day carbohydrate periodization
General guidance for healthy adults, not medical advice. Talk to a doctor or registered dietitian if you have a health condition, take medicines or have special dietary needs. Caffeine advice is for healthy adults only. EFSA's safe limit is 200 mg in one dose and 400 mg in a day.
