The effects of low and high glycaemic carbohydrates on endurance performance

The concept of glycaemic index (GI) was originally introduced to classify carbohydrate-rich foods, usually having an energy content of >80 % from carbohydrates, according to the differences in effects on post-meal glycaemia. The GI, which is a nutritional property of a carbohydrate-rich food, is defined as the incremental area under the blood glucose response curve following a 50 g glycaemic carbohydrate portion of a test food expressed as a percent of the response to the same amount of carbohydrates from a standard reference product taken by the same subject (FAO/WHO, 1998).

Carbohydrate-rich foods can be classified according to their GI values (glucose as the standard): high GI >70 (white bread, most white rices, corn flakes, extruded breakfast cereals, glucose); normal GI 55-70 (whole wheat products, basmati rice, sweet potato, sucrose); low GI 40-55 (most fruits and vegetables, legumes/pulses, whole grains, nuts, fructose) and very low <40.

On the other hand, is not easy to outline glycaemic index of foods rich in carbohydrates because many other factors in the diet (e.g. amount and type of dietary fibre, amount of dietary fat, energy density, physical properties, mode of preparation) are involved.

EFSA (European Food Safety Authority) expressed its negative opinion on the substantiation of health claims related to carbohydrates that induce low/reduced glycaemic responses and carbohydrates with a low glycaemic index. The claims effect was related to carbohydrates with a low glycaemic index (GI) and Impact on blood glucose / Glycaemic control / Glycaemic response or to maintain healthy cholesterol levels. The main cause of rejection of these claims was that the food constituents, carbohydrates that induce a low/reduced glycaemic response and carbohydrates with a low glycaemic index (e.g. <55), which are the subject of the health claims are not sufficiently characterised. On the other hand, there are also positive opinions concerning natural and artificial sugar replacers such as xylitol, sorbitol, mannitol, maltitol, lactitol, isomalt and sucralose for which EFSA approved the claims related to consumption of these substances and reduction of post-prandial glycaemic responses, furthermore the same opinions have been given for slowly digestible starch in starch-containing foods, beta-glucans from oats and barley and others.

Concerning this topic a recent human trial study has highlighted effects relevant to sportsmen. The study involved 10 well trained cyclists to investigate the effects of high and low glycaemic index (GI) 24 h recovery meals on the physiological responses and subsequent athletic performance, following a glycogen depleting protocol.

On day 1, subjects performed a glycogen depleting protocol after which they then consumed either high or low GI recovery diets over the next 24 h, which provided 8 g.kg BWˉ¹ of carbohydrate. On day 2, the subjects returned to the laboratory, 2-3 h postprandial, to perform a 40 km time trial (TT) on the Velotron cyclePro© ergometer. The results showed no significant differences between the two groups of subjects with respect to both physiological parameters (carbohydrate, fat oxidation and blood glucose concentration) and related to endurance performance.

The study suggests that type of carbohydrate intake (low GI or high GI carbohydrate) does not affect performance. This calls into question some long-standing formulation principles, and requires further research. The available evidence strongly supports carbohydrate intake in the context of sports; the final word on the use of low GI carbohydrates over high GI carbohydrates had not been said, and high GI carbohydrates still have a place.

Jacopo Angelucci – Sport nutrition Team

What does “light” mean? How far can the lack of nutrient profiles be pushed?

According to European Union Regulation 1924/2006, also known as the Nutrition and Health Claims Regulation (NHCR), the claim fat-free can be made when:

“A claim that a food is fat-free, and any claim likely to have the same meaning for the consumer, may only be made where the product contains no more than 0,5 g of fat per 100 g or 100 ml. However, claims expressed as ‘X % fat-free’ shall be prohibited.”

For example, a line of dairy products with 0,1 g of fat per 100 g can make such a claim,  can express it also as 0,1% fat, and may have features bordering on ligthness (without mentioning it, otherwise it would have to meet the requirements of reduced which are:
A claim stating that the content in one or more nutrients has been reduced, and any claim likely to have the same meaning for the consumer, may only be made where the reduction in content is at least 30 % compared to a similar product, except for micronutrients, where a 10 % difference in the reference values as set in Directive 90/496/EEC shall be acceptable, and for sodium, or the equivalent value for salt, where a 25 % difference shall be acceptable

).

That said, no fat or low fat claims do not imply that the product has low energy. With nutrient profiles practically dead (art. 4), this would seem ok, even when with the same “no fat” product line you have some flavors with low calories and some other flavors that practically have the same energy of the regular, full fat line. The consumer may think that the “no fat claim”, especially comparing superficially the two existing product lines, would imply a signficant reduction of energy as well , but this would be irrelevant from a regulatory standpoint.

Is it really so, or could it fall under the scope of misleading advertising? Authorities in at least some EU countries have proved ready to question a strict interpretation of Reg. 1924/2006, and fine companies under a broader interpretation, as int eh case of % cholesterol claims. Cholesterol content claims would be allowed under the Regulation’s annex, but appear to conflict with the principles of the Regulation.

Predictions are difficult to make, and we suggest caution with approaches as the one described (i.e., use the lack of profiles to push for products that are light only in appearance), especially for sports nutrition, which is often a soft target for regulators.

Sports Nutrition Team

Foods for sportsmen to be abolished

With regard to food intended to meet the expenditure of intense muscular effort, no successful conclusion could be reached as regard the
development of specific provisions due to widely diverging views among Member States and stakeholders concerning the scope of the specific legislation, the number of sub-categories of the food to be included, the criteria for establishing composition requirements and the potential impact on innovation in product development“. This is the reason for the European Commission to propose to abolish the category of foods for sportsmen. The proposal is here.

Alimenti per sportivi vicini all’abolizione

La Commissione Europea ha presentato proposta formale di abolizione della categoria “alimenti per sportivi” perché non è stato possibile fissarne le caratteristiche a livello comunitario. La destinazione d’uso per sportivi ricadrà dunque nell’ambito nazionale, secondo l’interpretazione delle norme vigenti, mentre i prodotti saranno ricompresi in altre categorie, dagli integratori agli arricchiti. La proposta dovrà essere vagliata da Consiglio e Parlamento.

US FDA publishes draft guideline on NDI in food (dietary) supplements.

The FDA has just published a draft guidance for US companies, concerning New Dietary Ingredient (NDI) used in food supplement. NDI can be somewhat likened to EU’s novel foods.

The 1994 ‘Dietary Supplements Health & Education Act’ (DSHEA) places an obligation on US companies to notify the FDA, when they want to market an NDI, providing also evidence of safety. Exceptions are ingredients used before 10/15/1994: they are ‘grandfathered in’ and considered safe.

The present guidance tends to maintain this stance, defining  some aspects that were not well clarified before. Ingredients used before 1994 in common foods have to be considered as NDI, if they are now used in food supplements. Ingredients used in food supplement, before than 1994 but outside the USA, have to be considered NDI as well.

Another specification of the present draft guidance is related to the manufacturing process; if it alters the chemical structure or composition of the ingredient, it makes it an NDI.

The draft guidance is open for comment.

Armando Antonelli – Sport Nutrition Team

Pubblicata dall’FDA la linea guida che definisce i Nuovi Ingredienti per Integratori Alimentari (NDI) negli USA.

L’FDA ha pubblicato l’attesa linea guida rivolta alle aziende del settore, che definisce più precisamente quando un ingrediente deve essere considerato un NDI, e cioè un Nuovo Ingrediente presente nelle formulazioni degli integratori alimentari, negli USA. Si tratta di qualcosa di simile alla norma comunitaria sui novel food.

Ciò è importante perché il ‘Dietary Supplements Health & Education Act’ (DSHEA) del 1994, obbliga le aziende americane che hanno intenzione  di immettere nel mercato integratori alimentari contenenti ingredienti nuovi a informare l’FDA di tale azione, allegando anche un certificato di sicurezza. Questo è valido per tutti gli ingredienti nuovi utilizzati negli integratori alimentari dopo il 15 Ottobre 1994. Tutti quelli utilizzati negli integratori, in America e prima di questa data, dispongono di una particolare autorizzazione per cui possono essere usati senza informare l’FDA, che li considera sicuri, in base alla normativa.

La linea  guida appena pubblicata tende a mantenere questa posizione specificando meglio alcuni aspetti, che  non erano ben definiti precedentemente. Infatti la guida specifica ad esempio che gli ingredienti utilizzati prima del 1994 in alimenti comuni, che volessero essere utilizzati negli integratori alimentari devono essere comunque considerati NDI. Lo stesso vale per gli ingredienti che prima del 1994 sono stati utilizzati negli integratori alimentari al di fuori degli USA.

La linea guida specifica, inoltre, che se gli ingredienti anche se già utilizzati negli integratori, subiscono dei processi di produzione che ne alterino la struttura o la composizione chimica  devono essere considerati  allo stesso modo NDI, e i produttori sono tenuti a fornire prove della loro sicurezza, un processo complesso, che non sempre è stato seguito, in particolare per i derivati natural-identici.

C’è però da tener presente che non esistono ‘elenchi ufficiali’ che definiscono gli NDI e che ogni produttore è responsabile di dimostrare se una sostanze è un NDI o meno.

Le linee guida al momento sono in fase di commento.

Armando Antonelli  – Sport Nutrition Team

The balanced and varied diet in action

Health claims can be made in advertising  only if a statement indicating the importance of a varied and balanced diet (and a healthy lifestyle) is included, according to EC Regulation 1924/2006. Of course, a possibility – when TV commercials are concerned – is to add on-screen text. Increasingly, however, this is at least complemented by showing a balanced meal, generally a breakfast with fruit, juice, milk and, for example, toast. It is a visual statement to the same effect. Though we have seen little use of this approach in the food supplement sector, it is certainly interesting. Recently, UK’s ASA (the Advertising Standards Authority) has upheld a complaintagainst Danone’s Nutricia ad.

While the Authority agreed that Nutricia could not compare their product,  Cow & Gate Growing Up Milk, to other categories of food, it noted “the relevant EC Regulation [Reg. 1924/2006] did not prevent a child being depicted drinking Cow & Gate Growing Up Milk as an accompaniment to a meal, to clearly illustrate the importance of a varied mixed diet in which the product might be one element“. At the same time, a compaint has not been upheld against Ferrero’s Nutella saying on the importance of a varied diet statement: “the ad showed each child eating only one slice of toast with Nutella and that the images also included other breakfast items such as fruit juice, milk and cereal”.

A recent example, in this respect, can be viewed in Italy with Danone’ Danaos ad which, regardless of other comments, shows a balanced breakfast, with juice being poured, etc.

– The Sports Nutrition Team –

%d bloggers like this: