Frequently Asked Questions

Carmen Martinez-Vidal BSc, mBANT, CNHC, NLP Dip, is the founder and lead practitioner at Nutrition Diets Clinic. She is a fully qualified and registered nutritional therapist and functional medicine practitioner with almost two decades of clinical experience. Carmen specialises in chronic gut issues, hormonal imbalances, fatigue, autoimmune conditions and metabolic health, using a personasiled approach that blends nutritional therapy and functional testing along with tailored health plans and supplement protocols.

Carmen is a qualified functional medicine practitioner and nutritional therapist with a BSc in Health Science: Nutritional Therapy from The University of Westminster. She qualified in 2010 and is registered with BANT and CNHC the main regulatory bodies for nutritional therapy in the UK. Carmen is also a certified Neurolinguistic Programming Coach (NLP) and undertakes CPD with a focus on gut health, hormonal health, skin health, immunity and mitochondrial function.

Functional medicine identifies the potential root cause factors of chronic illness rather than managing symptoms. Conventional care, including the NHS, is essential for acute issues, surgery, and pharmaceutical intervention, but is structurally less suited to slow-burning, multi-system problems like persistent bloating and other digestive symptoms, brain fog, fatigue, hormonal imbalance, food reactions or autoimmune conditions.

A functional consultation looks at how your body’s systems are working together, assesses your diet and lifestyle habits, uses targeted lab testing where indicated, and builds a personalised plan combining nutrition, lifestyle, and supplementation. It works alongside conventional care, not instead of it.

Nutrition Diets Clinic was founded in 2020 by Carmen Martinez-Vidal. The clinic operates entirely online, with at-home functional lab tests shipped directly to patients and consultations delivered via secure video call. We work primarily with clients across the UK, but also support clients in Europe.

You can cancel your consultation within 14 days of booking, unless you’ve booked an appointment during that time. If you need to reschedule, we require at least 48 hours’ notice. Refunds aren’t available after the session or if notice is shorter than 48 hours.

For more information please read our Refund Policy.

Patient data is handled in accordance with UK GDPR. Consultations are delivered via secure video call. Health records, test results, and consultation notes are stored on encrypted systems, accessed only by your practitioner, and never shared with third parties without explicit consent. The clinic adheres to the BANT and CNHC codes of professional conduct, both of which require strict patient confidentiality.

There’s no fixed sequence – clients enter the clinic through whichever route suits them best.

• If you’d like to talk first, book a free 15-minute Pre- Consultation Discovery Call. We’ll discuss what you’re experiencing and agree the right next step, which could either be a Comprehensive Consultation to review your full health history, and/or functional testing if appropriate.
• If you already know which test you want, order it directly from our online shop. Once your results are back, book a Lab Findings Review for professional interpretation of your results and guidance on next steps, or book a Comprehensive Consultation to review your test results alongside a full assessment of your health history, diet and lifestyle and get a health plan and supplement protocol tailored to your needs.

Either way, every interpretation, health plan and protocol is personalised by Carmen specifically, and all consultations are done online via secure video call.

Patients enter the clinic through different routes — some via a Discovery Call, others by ordering a test directly. Pricing is the same regardless of entry point.

It depends on the complexity of your case. Straightforward issues – mild bloating, skin reactions or brain fog with a clear nutritional cause – often resolve in two to four consultations over the course of a few months. Complex chronic conditions typically take six to twelve months, requiring additional check-ins to monitor progress and adjust your protocols.

There’s no obligation to commit to a package and consultations are booked one at a time — worked around your circumstances and needs.

Functional tests measure markers that conventional NHS testing doesn’t routinely include — gut microbial balance, food sensitivities, hormone metabolites, nutrient status, mitochondrial function. Standard blood work tells you whether something is in the normal range; functional testing tells you whether your systems are working optimally, which is a more useful question for someone with chronic symptoms.

You order through the shop, the kit is posted to you, you collect the sample at home, and return it by prepaid courier. Results come directly to the clinic and are are then shared with you securely.

Nutrition Diets Clinic partners with four of the leading functional laboratories, each chosen for the quality of their testing in specific areas:

• Nordic Labs — comprehensive stool analysis (GI MAP), food sensitivity panels, DUTCH hormone testing
• Genova Diagnostics — comprehensive nutritional and metabolic panels, including NutrEval
• CNS Labs — specialist hormonal and neurotransmitter testing
• Lifecode — genetic and methylation testing

Five main categories:

• Gut health — comprehensive stool analysis (GI MAP), SIBO breath testing, intestinal permeability markers (leaky gut), H. pylori
• Food sensitivities and intolerances — IgG-based panels covering 200+ foods, plus targeted gluten and dairy testing
• Hormonal health — DUTCH Plus, thyroid panels, female and male hormone testing
• Metabolic and nutritional — NutrEval, vitamin and mineral panels, methylation, organic acids
• Skin and inflammation — markers relevant to acne, rosacea, eczema, and chronic inflammation

Browse the full range on our online shop, organised by category.

Tests range from £75 for a single-marker test like Vitamin D up to £675 for the most comprehensive nutritional panel (NutrEval). Most testing sits between £200 and £400.

Anchor prices for the most commonly ordered tests:

• Comprehensive Stool Test (GI MAP) — £375
• Comprehensive Stool Test (GI MAP) plus Zonulin — £440
• SIBO Breath Test — £195
• Food Sensitivity & Intolerance Test — £275
• DUTCH Plus + CAR Hormone test — £350
• Methylation Genetic test — £350
• NutrEval — £675
• Vitamin D Test — £75

Full pricing is on each test’s product page in the online shop.

Yes. Tests can be ordered directly through the shop without a prior consultation, and many clients do.

We strongly recommend booking a Lab Findings Review once your results come back. Functional test results are not designed to be self-interpreted — the markers are meaningful only in the context of your specific symptoms and clinical picture, and the protocol that follows is where the clinical value lives. Buying a test without an interpretation is buying half a service.

Test kits typically arrive within one to two working days of ordering. Turnaround from sample collection to results varies:

• Stool tests — three weeks
• Hormone testing (DUTCH) — three weeks
• Food sensitivity panels — one to two weeks
• Genetic and methylation testing — two to three weeks

Results come directly to the clinic once the lab has processed your sample. If you’ve booked a Lab Findings Review, we usually meet within one week of your results landing to clinically interpret your report.

Yes. The clinic ships test kits to mainland Europe, and most international destinations. Shipping costs and times vary by location and lab and are calculated at checkout. Prepaid return courier is included for tests requiring sample return to a UK or European lab; for some destinations, additional courier arrangements may apply, which we’ll confirm before dispatch. Please note that we are not responsible for any import duties applied to international orders.

Test kits are sealed medical products and are typically dispatched within one to two working days of purchase. Cancellation is only possible if the order is caught before it has been dispatched — please contact the clinic immediately if you need to cancel your order. Once a kit has been dispatched, refunds are available only if it arrives faulty, damaged, or is not the test that was ordered. Refunds outside the standard policy are considered case by case.

Full details are set out in the Refund Policy.

Test results are sent directly from the lab to Nutrition Diets Clinic. You will be notified as soon as these are uploaded by a practitioner to your secure Client Folder. If a Lab Findings Review (45 mins, £95) has been booked, a practitioner will review and interpret your results in a focused one-to-one session, explaining what the your health data means in the context of your symptoms and guide you on the next possible steps.

For an in-depth review of your test results alongside full assessment of your health history, diet and lifestyle (health questionnaire and 7 day food and symptoms diary provided shared in advance) we recommend booking a Comprehensive Consultation (60 mins, £175) with a practitioner who will create a personalised health plan and supplement protocol targeting the suspected root causes of your symptoms.

AI tools can be a useful starting point for understanding what individual markers measure or how a test broadly works. However, they are not a substitute for clinical interpretation by a qualified practitioner, and there are two specific risks worth knowing about.

Misinterpretation risk. Functional test results are not just about whether a marker is in or out of range — what matters is the pattern across multiple markers, how they relate to each other, and what they mean in the context of your symptoms. AI tools are good at processing data but unreliable at the clinical reasoning that connects it. They also make errors with a high degree of confidence — misreading reference ranges, confusing units, fabricating clinical citations and providing misleading recommendations — that a trained human practitioner would catch.

Data risk. Uploading a test report to a consumer AI tool means your health data is processed on third-party servers, often under terms that permit commercial use of your personal information including model training. Sharing test results with a regulated practitioner in the UK is governed by GDPR and clinical confidentiality codes; sharing them with ChatGPT is not.

Even if you do choose to use an AI tool to interpret your results, it’s always recommended to seek a second-opinion from a qualified medical professional.

A qualified functional medicine practitioner does several things AI cannot:

• Reads results in clinical context specific to your symptoms and condition — the same number on a stool test or hormone panel can mean different things in different patients. This really matters as it’s the difference between knowing what the numbers say, and what the numbers actually mean
• Recognises patterns across markers — clinical insight comes from how results relate to each other and to a patient’s symptoms, not from any single number or marker within a reference range
• Builds a sequenced protocol — what to address first, what to combine, what to avoid, and how to adjust as the body responds
• Takes clinical responsibility — a qualified practitioner is professionally accountable for the advice they give, holds insurance, and is regulated by professional bodies. AI tools are not.

AI is a useful information tool. Clinical judgement is what turns information into a safe, personalised protocol.

Functional test results are dense, often counter-intuitive, and rarely interpretable from any single marker in isolation. What matters is the pattern across results, what each finding means in the context of your symptoms, and what to do about it.

The Lab Findings Review (45 min, £95) is where the test you’ve paid for becomes actionable. Your practitioner reviews the results in advance, identifies the patterns that matter, and walks you through what’s likely driving your symptoms, guiding you on the possible next steps. The clinical value isn’t in the test itself — it’s in the interpretation and the protocol that follows.

For a deeper assessment that includes full assessment of your health history, food and symptoms diary, and a personalised action plan, the Comprehensive Consultation (60 mins, £175) is the appropriate next step for you.

The Natural Dispensary is a UK-based supplier of practitioner-grade supplements, used widely across the functional and nutritional medicine field. Nutrition Diets Clinic patients receive a 10% life-time discount on all supplement and health product orders placed through The Natural Dispensary using the clinic’s referral code, which is shared during the consultation.

Please note that supplements purchased via The Natural Dispensary are subject to their own returns and refund policy.