Preparing a Food Diary for Your Dietitian

Q: How many days should I keep a food diary before seeing a dietitian?

The British Dietetic Association recommends keeping a detailed food diary for at least 3 to 7 days before your first appointment, including at least one weekend day. This gives your dietitian a realistic snapshot of your usual eating patterns. If you have been asked to track symptoms as well, such as for IBS or allergy investigation, 2 to 4 weeks of data is more useful. Start as soon as your appointment is booked rather than waiting until the last few days.

Q: What do dietitians want to see in a food diary?

Dietitians want to see a complete and honest picture of your usual intake. This includes all meals, snacks, and drinks (including water), approximate portion sizes, the time of each meal or snack, how food was prepared (boiled, fried, grilled), brand names for packaged products, and any condiments, sauces, or cooking oils used. If relevant to your referral, they may also want mood or symptom notes alongside your food records.

Q: How do I get referred to a dietitian on the NHS?

In most cases, you need a referral from your GP. Book an appointment with your doctor, explain your concerns (such as suspected food intolerances, weight management difficulties, or managing a condition like IBS or diabetes), and ask for a referral to a registered dietitian. Waiting times vary by area but are typically 4 to 12 weeks. Alternatively, you can see a private dietitian registered with the BDA without a referral, though you will need to pay for the consultation.

Q: Should I eat normally when keeping a food diary for my dietitian?

Yes, absolutely. One of the most common mistakes is changing your eating habits because you know someone will see your diary. Your dietitian needs to see what you actually eat, not an idealised version. If you normally have a takeaway on Friday, have biscuits with your afternoon tea, or skip breakfast three days a week, record that honestly. Your dietitian is there to help you from where you are, not to judge you.

TL;DR: Start your food diary as soon as your dietitian appointment is booked, ideally logging for at least 3 to 7 days including a weekend. Record everything you eat, drink, and snack on, with portion sizes, timing, preparation methods, and brand names. Be completely honest — your dietitian needs to see your real eating habits, not your best days. A digital food diary app can provide more detail and accuracy than paper and is perfectly acceptable to bring to your appointment.

You have got a dietitian appointment coming up, and you have been told to bring a food diary. But what exactly should you record? How far in advance should you start? And does it matter whether you use an app or a notebook?

Getting your food diary right can make the difference between a productive appointment that gives you a clear plan and one that leaves both you and your dietitian without enough data to work with. Here is everything you need to know.

What Dietitians Actually Want to See

Dietitians review food diaries every working day, and they consistently report the same priorities. Understanding what they are looking for will help you provide the most useful information possible.

Complete meals and snacks

Every single thing you eat needs to be recorded, including meals, snacks, nibbles while cooking, food from colleagues' desks, and anything you eat while standing in front of the fridge. The small things you might dismiss as "not worth logging" can be exactly the pieces your dietitian needs to see.

All drinks

This is one of the most commonly missed categories. Your dietitian needs to see your full liquid intake, including water, tea and coffee (with milk and sugar details), juices, smoothies, fizzy drinks, alcohol, squash, and any supplements or protein shakes. A medium latte with whole milk contains around 200 calories and a significant amount of saturated fat — drinks are food in liquid form, and they matter.

Portion sizes

You do not need to weigh everything on a kitchen scale, though doing so for the first few days can be eye-opening. Household measures are perfectly acceptable: "1 large handful," "2 heaped tablespoons," "half a standard plate," "1 medium banana." The goal is to give your dietitian a realistic sense of quantity, not a laboratory measurement.

Timing

Note the approximate time of each meal and snack. Meal timing and spacing can have a significant impact on energy levels, blood sugar management, and digestive health. Your dietitian may identify patterns you had not considered, such as long gaps between meals leading to overeating later, or late-night snacking affecting sleep quality.

Preparation method

The same food prepared differently can have very different nutritional profiles. A baked potato and a portion of chips are both potatoes, but their calorie and fat content are vastly different. Note whether food was boiled, steamed, grilled, fried, roasted, or raw, and mention any added oil or butter used in cooking.

Brand names for packaged foods

Different brands of the same product can vary significantly in their nutritional content. "Yoghurt" is far less useful than "Fage Total 0% Greek Yoghurt, 170g pot." If you are using an app with barcode scanning like NutraSafe, this information is captured automatically.

How Long Before Your Appointment to Start

The British Dietetic Association (BDA) recommends a minimum of 3 to 7 days of food diary data before your first appointment, including at least one weekend day. However, the ideal approach depends on why you are being seen:

Reason for Referral	Recommended Tracking Period
General nutrition assessment	3 to 7 days (including weekend)
Weight management	7 to 14 days
IBS or digestive issues	2 to 4 weeks (with symptom tracking)
Suspected food intolerance	2 to 4 weeks (with reaction tracking)
Diabetes management	7 to 14 days (with blood glucose if relevant)
Eating disorder recovery	As advised by your care team

The most important thing is to start as soon as your appointment is booked rather than leaving it to the last few days. If your appointment is in six weeks, that gives you time to establish a natural tracking habit so your diary reflects your genuine eating patterns rather than a rushed last-minute effort.

Start Early

Book your appointment, then start your food diary that same day. The longer you track, the more useful data your dietitian has to work with, and the more natural the process becomes.

Common Mistakes That Waste Your Appointment

Dietitians see the same mistakes regularly. Avoiding these will make your appointment significantly more productive.

1. Eating differently because you are tracking

This is the single most common problem. Many people subconsciously "clean up" their diet when they know a professional will review it. Your dietitian has seen every eating pattern imaginable — they are not there to judge you. They need to see what you actually eat, including the takeaways, the biscuits, the skipped meals, and the wine on Friday evening. An idealised food diary leads to recommendations that do not fit your real life.

2. Forgetting drinks, oils, and sauces

A splash of olive oil in the pan, ketchup on the side, sugar in your tea, a glass of juice with breakfast — these additions can account for 300 to 500 calories per day. They also provide important information about your fat, sugar, and sodium intake. Make a conscious effort to log every condiment and cooking addition.

3. Logging meals from memory at the end of the day

Research consistently shows that food recall accuracy drops significantly even a few hours after eating. People forget snacks, underestimate portions, and omit drinks. Log each meal as close to eating it as possible. If you are using a phone app, it takes 20 to 30 seconds and is far more accurate than trying to reconstruct your day at bedtime.

4. Only tracking weekdays

Weekend eating patterns are often very different from weekdays. Larger portions, more alcohol, eating out, later meals, and different food choices are all common. Your dietitian needs to see the full picture, including Saturday and Sunday. If your tracking period is only 3 days, make sure at least one of them is a weekend day.

5. Skipping "bad" days

If you had a particularly indulgent day and feel tempted to leave it out of your diary, that is exactly the day your dietitian most needs to see. Understanding your full range of eating — including the days that feel less healthy — is essential for creating a realistic and sustainable plan.

Why Digital Diaries Beat Paper

While a handwritten food diary is better than no diary at all, digital apps offer meaningful advantages for dietitian appointments specifically:

More accurate nutritional data — apps can automatically calculate calories, macronutrients, and micronutrients, giving your dietitian a detailed nutritional picture rather than just a list of foods
Barcode scanning — captures exact product details including brand, ingredients, and portion sizes in seconds
Better adherence — research shows people log more consistently with apps because their phone is always with them
Legibility — no more trying to decipher rushed handwriting or interpreting abbreviations
Easy to review during the appointment — scroll through your diary on your phone screen together with your dietitian
Historical data — if you continue tracking between appointments, your dietitian can review progress over time

NutraSafe is particularly well suited for dietitian preparation because it combines a UK-specific food database with barcode scanning, nutritional breakdowns, and food reaction tracking. If you are being seen for IBS or suspected intolerances, having food and symptom data in the same app makes the appointment significantly more efficient.

The NHS Dietitian Referral Process

Understanding how the referral process works in the UK helps you prepare effectively:

Getting referred

In most cases, you need a referral from your GP to see an NHS dietitian. Book an appointment with your doctor, explain your dietary concerns or the condition you need help managing, and ask for a referral. Common reasons for referral include IBS and digestive issues, weight management, diabetes (Type 1 or Type 2), food allergies or intolerances, coeliac disease, malnutrition or unintentional weight loss, and eating disorder recovery support.

Waiting times

NHS dietitian waiting times vary significantly by region and reason for referral, but typically range from 4 to 12 weeks. Use this waiting period productively by starting your food diary as soon as you know the appointment is booked.

Private dietitians

If you would prefer not to wait, you can see a private dietitian without a GP referral. Make sure they are registered with the Health and Care Professions Council (HCPC) and ideally a member of the British Dietetic Association. The title "dietitian" is protected by law in the UK, meaning only qualified, registered professionals can use it. Be wary of "nutritionists" or "nutrition therapists" as these titles are not legally protected.

What to bring to your appointment

Your food diary (phone app or paper)
A list of any supplements you take
Any relevant test results (blood tests, allergy tests)
A list of medications you are taking
Your questions written down — it is easy to forget in the moment

Appointment Tip

Write down your top 3 questions before your appointment. Dietitian consultations are typically 30 to 60 minutes, and having your priorities clear ensures you cover what matters most to you.

A Sample Day in Your Food Diary

Here is an example of what a well-recorded day looks like, compared to a poorly recorded one:

Unhelpful entry

"Breakfast: cereal. Lunch: sandwich. Dinner: chicken and rice. Snack: biscuits."

Useful entry

7:30am — Breakfast: Weetabix x2 with semi-skimmed milk (about 200ml), 1 sliced banana, 1 tsp honey. Cup of tea with semi-skimmed milk, no sugar.

10:15am — Snack: 1 Granny Smith apple. Glass of water.

12:45pm — Lunch: Tesco BLT sandwich (pre-packed, white bread). Small bag of Walkers Ready Salted crisps (25g). Diet Coke (330ml can).

3:30pm — Snack: 2 digestive biscuits. Cup of tea with semi-skimmed milk.

7:00pm — Dinner: 2 chicken thighs, skin on, pan-fried in about 1 tbsp olive oil. Basmati rice (roughly 1 cup cooked). Broccoli (about 4 florets, steamed). Sriracha sauce, about 1 tsp.

9:00pm — Snack: Small bowl of strawberries (about 8). Muller Corner yoghurt, strawberry.

Throughout the day: About 4 glasses of water, 2 cups of tea.

The difference is clear. The detailed entry gives your dietitian everything they need to assess your nutritional intake, identify potential improvements, and create a realistic plan that fits your actual eating habits.

Prepare for Your Appointment

NutraSafe makes food diary preparation easy with barcode scanning, a UK food database, and automatic nutritional breakdowns your dietitian will appreciate.

Download NutraSafe Free

Frequently Asked Questions

How many days should I keep a food diary before seeing a dietitian?

The British Dietetic Association recommends at least 3 to 7 days of detailed logging, including at least one weekend day. For IBS or food intolerance investigations, 2 to 4 weeks of data is more useful. Start as soon as your appointment is booked rather than waiting until the last few days.

What do dietitians want to see in a food diary?

Dietitians want to see a complete, honest picture of your usual intake. This includes all meals, snacks, and drinks (including water), approximate portion sizes, the time of each meal, how food was prepared (boiled, fried, grilled), brand names for packaged products, and any condiments, sauces, or cooking oils used.

How do I get referred to a dietitian on the NHS?

You typically need a referral from your GP. Book an appointment, explain your concerns, and ask for a referral to a registered dietitian. Waiting times vary by area but are usually 4 to 12 weeks. You can also see a private dietitian registered with the BDA without a referral, though you will need to pay for the consultation.

Should I eat normally when keeping a food diary for my dietitian?

Yes, absolutely. Your dietitian needs to see what you actually eat, not an idealised version. If you normally have a takeaway on Friday, have biscuits with your afternoon tea, or skip breakfast, record that honestly. Your dietitian is there to help you from where you are, not to judge you.

Is a phone app acceptable as a food diary for a dietitian appointment?

Yes, most dietitians are happy to review a digital food diary. Many prefer it because apps capture more detail, include nutritional breakdowns, and are easier to read than handwritten notes. Apps with barcode scanning and UK food databases can provide particularly accurate records that make your appointment more productive.