Healthspan revisited: what can a food expert actually say in a VAT case?

The Upper Tribunal has told the First-tier Tribunal how to decide whether expert evidence is allowed. Less has been said about what it means for the expert who now has to write the report. Here I look at the decision from the witness box rather than the bench.

In May I wrote about HMRC v Healthspan Ltd [2026] UKUT 00194 (TCC) and what it teaches those instructing an expert. That piece was written for counsel and solicitors. This one is written for the expert. Why return to it? Because the Upper Tribunal did something unusual. It did not just correct the test and send the case back. It remade the decision itself and drew a line around what a food expert may say. That line is now the clearest statement we have of where nutritional science ends and statutory interpretation begins in a VAT "food" case.

If you are a nutritionist, food scientist or toxicologist asked to give evidence on zero-rating, you need to know where that line sits before you write a word.

Where exactly is the line?

A quick recap. Healthspan claims over £56 million in overpaid VAT on 316 food supplement products, from turmeric capsules and cod liver oil to multivitamins and probiotics. It says they are zero-rated as "food of a kind used for human consumption". HMRC applies an "ordinary person" multifactorial test. Healthspan argues for a test based on nutritional purpose or content.

The Upper Tribunal gave Healthspan permission for expert evidence on one topic only. It is worth reading the wording closely, because this is now the expert's brief (at [74]).

Permission was granted for evidence on:

• The nutritional composition and nutritional significance of the disputed products;

• Whether particular ingredients are properly characterised as nutrients; and

• Where relevant, their physiological role in supporting life and bodily function.

Permission was refused for evidence on:

• The meaning of the statutory term "food";

• Anything that seeks to justify one party's preferred legal definition;

• How the products are regulated or regarded by government or scientific bodies; and

• An opinion on the ultimate VAT classification.

The broader limbs on "the scientific understanding of food" and the "modern diet" were refused outright. HMRC's counsel called the first of these the "broadest possible licence for abstract musings" (at [70]). The Tribunal agreed that it would turn the expert into "an advocate for one party's preferred definition" (at [71]).

Lesson for experts: Your opinion on what "food" means is not evidence. It is argument. If a sentence in your report would still make sense in counsel's skeleton, it probably belongs there and not in your report.

Why can't the tribunal just read the label?

This was HMRC's best point. Much of what the expert would say, it argued, can be read off the labels. Identifying vitamins or proteins is within the ordinary knowledge of the tribunal (at [66], [73]).

The Upper Tribunal disagreed, and its answer is the most useful passage in the judgment for any food scientist. There is "a material distinction between identifying constituents and evaluating nutritional significance and physiological role" (at [75]). Whether a substance is properly characterised as a nutrient, and what it does in the body, "is not necessarily a matter within ordinary knowledge".

That is exactly where the expert earns their place. A label tells you that a capsule contains 500 mg of turmeric extract. It does not tell you whether curcumin is a nutrient, what its bioavailability is, or whether it contributes to keeping the body alive and enabling it to function and develop. That last phrase matters. It mirrors the CJEU's formulation in X (C-331/19), on which Healthspan's pleaded definition relies (at [65]).

The Tribunal also noted that expert evidence on nutritional value has history in VAT food cases: Arthro Vite Ltd v HMCE(1996), Telemara Ltd v HMRC [2025] UKFTT 01123 (TC) and Bottled Science Ltd v HMRC, where the problem was a lack of evidence on nutritional value (at [77]). But it was careful to add that it was not laying down a general rule. Each case turns on its pleadings.

Lesson for experts: Do not repeat the label back to the tribunal. Your value lies in the step after identification: is it a nutrient, and what does it do? If your report does not take that step, it adds nothing the tribunal cannot do itself.

How should the expert now write the report?

The permission stage is no longer a formality that can be fixed later. The FTT had admitted the evidence on the basis that HMRC could challenge admissibility once the report arrived. The Upper Tribunal said that is "not a proper substitute for permission-stage control" (at [53]). It also said the FTT had ignored the cost to HMRC of analysing, challenging and answering the evidence (at [54]).

For the expert, that changes the order of work. In my view it points to five practical steps.

1.     Get involved before the application is made. The Tribunal will now ask for the pleaded issues and "what precise question or questions" the expert is to answer (at [49]). The expert is best placed to say which questions science can answer. A list of broad topics, as Healthspan learned, will not do (at [46]).

2.     Work from the permission order, not the letter of instruction. If the two differ, the order wins. Quote the permitted scope at the start of the report and come back to it in each section.

3.     Plan for scale. HMRC warned of an "avalanche" of material across 316 products (at [66]). A sensible report will group products by nutrient type and physiological role, explain the method once, and then deal with each group. It will not write 316 essays.

4.     Leave out regulation. The FTT had recorded Healthspan wanting evidence on how the products are "regarded by the body of scientific opinion and why they are regulated in a given manner by the Government" (at [52]). That is now expressly outside the permission. EFSA opinions and Article 13 claims may be tempting background for a food lawyer. In this report they are off limits unless they go directly to nutritional function.

5.     Stop before the conclusion. Do not say the products are or are not "food". Say what each one contains, whether those constituents are nutrients and what they do. The tribunal will take it from there.

Lesson for experts: HMRC described the risk of the expert becoming an "amplifier" of the party's legal case (at [66]). Read your draft as opposing counsel would. Every paragraph that amplifies is a paragraph they will use to attack your independence.

There is a wider point here too. I have written before about choosing experts carefully and about whether an expert can hold a view. Healthspan adds a third test. The best expert is not the one who knows the most about food. It is the one who can stay within a narrow question and answer it well.

The bottom line

Healthspan has not decided whether a turmeric capsule is food. That question is still to come. What it has done is define the food expert's job in VAT cases more tightly than any decision before it.

The expert explains composition, nutrient status and physiological role. The tribunal decides what the law means. The two must not blur.

The Upper Tribunal also left a door open. In "exceptional cases" the overriding objective may still justify evidence that does not strictly meet the "reasonably required" test (at [42]). But such cases will be rare, and no expert should plan a report around one.

For those of us who give this evidence, the message is simple. Narrow is not a limitation. Narrow is what makes the evidence admissible, credible and worth paying for.

If you are considering expert evidence in a VAT food classification dispute, or need help framing the questions for a permission application, please get in touch.

Dr Mark Tallon LLM PhD ERT is a food lawyer, regulatory toxicologist and expert witness in food classification and VAT disputes.

Source: HMRC v Healthspan Ltd [2026] UKUT 00194 (TCC), Upper Tribunal (Judge Swami Raghavan and Judge Nicholas Paines KC), judgment 15 May 2026.