Nutrition Research Highlights 4|2011
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This newsletter is published by the Nutrition & Health Group of the JRC’s Institute for Health and Consumer Protection. Regularly surveying the top nutrition and medical journals, we select the most recent news on nutrition research, relevant to current societal debates or policies. These are then summarised as “News” items or presented as a “View”, comprising an analysis and expert opinion. Enjoy your reading!
Do you sometimes feel that as the years pass not only your age but also your weight increases? A recent study (1) analysed weight changes and specific diet and lifestyle behaviours over time in healthy, non-obese adult U.S. men and women. The average weight gain across the groups of people analysed (over 120 000) was of approximately 1.5kg every 4 years, indicating a continuous positive energy balance over the years. The culprits appear to be the usual suspects: consumption of potato chips, potatoes, sugar-sweetened beverages and red meat (both processed and unprocessed) were strongly associated with increased long-term weight gain and so were alcohol use, smoking cessation, over- (> 8 hours) and under- (< 6 hours) sleeping as well as television viewing. Not surprisingly, physical activity was associated with weight loss, as were the intakes of vegetables, whole grains, fruits, nuts and yogurt. Interestingly, the study does not confirm that high energy density, fat content and added sugars are the underlying factors causing the weight gain. The weight gain was instead associated with the consumption of refined or processed foods as well as liquid carbohydrates. Indeed, consuming unprocessed foods such as whole grains, fruits, nuts, and vegetables was associated to weight loss while low-fat, sugar-free and low energy density foods were not. The authors speculate that starches and refined grains are less satiating and increase subsequent hunger signals and total caloric intake while unprocessed high-fibre foods augment satiety, are more slowly digested and their increased consumption would replace other more processed foods in the diet. Nevertheless, there are still many gaps in our understanding of how diet characteristics alter hunger, satiety, bioavailability, metabolism and ultimately energy balance. Αnother investigation (2), using data from various US national nutrition and food intake surveys looked at energy balance from another angle. The study shows that in the US, the average daily total energy intake increased from 1,803 kcal in the late 70s to 2,374 kcal in 2003–06. The researchers focused on three possible causes for this increased energy intake: 1) increased frequency of meals and snacks 2) increased portion sizes and 3) changes in the energy density (calories) of the foods and drinks consumed. They report that larger portion sizes and more meals and snacks per day are mainly to blame for the increased energy intake.
You may think that the findings in these articles are not surprising and you are probably right. However, they are important because they provide the sort of solid science-based evidence needed for doctors, nutritionists and policy makers to propose and prioritize preventive obesity measures. And for each one of us, weight change is a very good and easy metric for evaluating an energy imbalance that can be controlled on the scale at home! (PM)
Photo: Food contribution to weight gain or loss. N Engl J Med 2011;364:2392-404. Copyright © 2011 Massachusetts Medical Society
With obesity and related health issues (diabetes, cardiovascular diseases etc.) on the rise worldwide, public health policy is trying to make every effort to help citizens to choose healthy diets and lifestyles. Recent advances have resulted in updated dietary reference values for nutrient (fat, protein, carbohydrates, vitamins, minerals, fibre) intakes that should not only ensure prevention of nutrient deficiencies but also of nutrient imbalances and overeating. Nevertheless, these scientific values have to be translated into clear and usable advice on what foods to consume and in what quantities. In this context, the United States Department of Agriculture (USDA) has recently launched (1) MyPlate, "a new reminder to help consumers make healthier food choices". MyPlate is a modern and simple icon, replacing the former USDA representation of the food pyramid. The MyPlate icon is part of a larger campaign which also includes a dedicated website, ChooseMyPlate (2). Michelle Obama points to the heart of the issue. “When mom or dad comes home from a long day of work, we’re already asked to be a chef, a referee, a cleaning crew. So it’s tough to be a nutritionist, too. But we do have time to take a look at our kids’ plates. As long as they’re half full of fruits and vegetables, and paired with lean proteins, whole grains and low-fat dairy, we’re golden. That’s how easy it is.” The icon is indeed simple and easy to understand but its simplicity has also been criticised. Oil, fat and sugar are not depicted in Myplate, notes Christina Munsell, RD, a research assistant at Yale University’s Rudd Center for Food Policy & Obesity (3). And the Times reports the opinion of Marion Nestle, a professor of nutrition at New York University, that comments on the section of the plate labelled "protein" as being confusing, because it does not clarify that grains and dairy are important sources of protein (4), and unnecessary, because most Americans alreday get more protein than they need. These are certainly very valid points but in complex issues such as nutrition habits it may be easier and more effective to focus on simple messages at a time. In this case, the message appears to be 'Make half your plate fruits and vegetables' and that's not only nutritionally wise but also quite tasty. (SC)
Image: ChoseMyPlate icon. Copyright © U.S. Department of Agriculture - web site
A recent study (1) published in the Lancet has launched yet another red alert for diabetes as globally the number of people diagnosed with this disease has more than doubled between 1980 and 2008 (from 153 to 347 Million). Although global population growth (51% increase from 1980 to 2008 (2) and ageing are important causes of this increase the authors also observed a steady increase in mean fasting plasma glucose (FPG) levels, which correlated well with increases in body mass index (BMI). Since diabetes is often diagnosed by exceeding a FPG threshold level (e.g. 7.0 mmol/L or 126 mg/dL, American Diabetes Association) this mean FPG increase will inevitably result in a greater part of the society being diagnosed with diabetes. Interestingly, the strength of correlation between FPG and BMI varies over the globe indicating that genetic factors, foetal and early life nutritional status, diet quality and physical activity levels contribute to FPG and diabetes trends beyond their effect on BMI. The same study therefore concludes that primary prevention strategies are urgently needed to control weight, promote physical activity and improve diet quality. In fact, there is international consensus supported by several large, randomised clinical trials that increased physical activity and dietary management is fundamental in prevention and initial treatment of type 2 diabetes (formerly called "adult-onset diabetes") (3, 4). Recent data even suggest that more intensive dietary consultation (every 3 months and monthly nurse support) with or without physical activity consultation (towards 30 min of fast walking, 5 days/week) result in additional benefits after 6 and 12 months in overweight subjects with newly diagnosed diabetes over a standard therapeutic care (initial dietary consultation and 6-month follow ups) as practised in the southwest of England (5). Dietary consultation recommended foods with lower energy density, fat content and glycaemic index (i.e. blood glucose response after consumption of a given food) as well as advice on portion sizes and consumption frequencies. In contrast to several other studies (e.g. 6, 7), in this particular study the additional physical activity did not appear to further improve the situation. The authors speculate that the early state of diabetes may be a reason for this observation. Moreover based on qualitative interviews of their study participants, they suggest that the simultaneous modification of two behaviours weakened the effect of both. They state that "people use a trade-off system in which they reward themselves for additional exercise with increased food intake" (5). The pivotal importance of diet in managing type 2 diabetes has also been highlighted in another recent study where researchers from Newcastle University have reported that a very strict low energy diet (consisting of a liquid formula and non starchy vegetables, about 600 kcal/day) could revert the hallmarks of type 2 diabetes, insulin resistance and beta-cell failure in 11 recently-diagnosed type 2 diabetes individuals (8). This explorative study and the former trial (5) along with other previous major trials (e.g., 6, 9, 10) reinstate the importance of lifestyle interventions, education and support in preventing and managing type 2 diabetes (in particular recently diagnosed cases) and improving the life quality of diabetes type 2 patients. (PM)
This month has seen a major breakthrough in EU food labelling and consumer information as, after three years, long debates and over 3000 amendments, a proposal for a new legislation has finally been given a green light by the Parliament. The story goes back to 2008 when the Commission submitted a legislative proposal to the Parliament and Council on the provision of food information to consumers, COM(2008) 40 final (1), to combine and replace the two directives, Directive 2000/13/EC (2) of the European Parliament and of the Council and the Council Directive 90/496/EEC (3). The amended proposal is now ready for approval by the Council and it could be published in the EU Official Journal as early as end of October. The main objectives of the new legislation are to enable consumers to make informed, safe, healthy and sustainable food choices by providing them with easily understandable, relevant, useful and legitimately expected information as well as ensuring a pro-competitive, smooth functioning internal market (4). The new EU food labelling rules will apply to all food sold to the final consumer with the exception of fresh, non pre-packed food and hand-crafted products. What are the main novel points put forward by the new legislation? While not exhaustive, we are presenting five of the novel points introduced by the recently agreed legislation below:
- In addition to current mandatory information such as name of the food, the net quantity and expiry date, the new legislation calls for mandatory nutritional information that will include energy value in calories, amounts of fat including saturated fats, carbohydrates including sugars, proteins and salt expressed per 100 grams (g) or 100 millilitres (ml), thus allowing for comparisons between products. To ensure consumers can easily find and read this information, it should be presented together in a table following a set of guidelines to ensure legibility.
- Currently all ingredients, including allergenic ones, must be indicated in the labels. With the new proposal however the allergenic substances must be highlighted in the ingredient list, so that consumers can spot them 'at a glance'. This measure also applies to foods that are pre-packed for direct sale, packed at the moment of purchase or served in restaurants.
- Another issue touched by the new legislation is 'imitation' foods. These refer to products such as cheese-like products made from vegetable sources or what is to be labelled "formed meat" or "formed fish". There will also be rules in place to ensure that consumers are not misinformed by the name of products and the appearance and images present on the package.
- Currently the country of origin of foods, such as beef, honey, olive oil, fresh fruit and vegetables must be stated on the label. The new legislation will extend the "Country of origin" labelling to fresh meat from swine, sheep, goat and poultry.
- The source of the vegetable oils (i.e. from which plant they were extracted) used in the production of the product will also have to be indicated in the label. This comes as a response to the fact that unsustainable palm oil plantations endanger rain forests and the wildlife they hosts and will allow the environmentally minded consumer to discriminate against products that contain it.
While we should all certainly be pleased that an agreement has been reached and food labelling will finally be governed by a more adequate piece of legislation, not all the actors involved in the process are entirely happy with the end-result. Several measures proposed await additional evidence for being re-evaluated. This is the case for labelling or restricting usage of trans fats* or extending the country of origin labelling to other food categories and the Commission will be looking into these options in the near future.
Another reason for discontent was the rejection of the so-called front-of-pack (FOP) nutrition declaration or 'FOP labelling' proposal. The idea behind FOP labelling is a simple one - should all products in a shelve display in the front-of-pack for example their energy content per 100g, a consumer wary of his weight could easily choose a low calories product. The US Food and Drug Administration (FDA) together with the Institute of Medicine of the National Academies, is currently developing a science-based FOP labelling system (5) to ensure that US consumers will have access to well-thought clear nutritional information . As the initial Commission's proposal has been rejected, the new European legislation will not include mandatory FOP labelling. There is however a commendable provision for voluntary inclusion of nutrition information on the front of packs, which, as acknowledged by the European Commission 'provides the basis for further consideration of this issue in the future'. While we do hope that socially-minded and responsible companies will take this opportunity to help the consumer identifying the products that may best suit him/her, we note that to be effective, voluntary labelling must also follow some rules. Indeed, in the US, voluntary initiatives such as Smart Choices have been heavily criticised and suspended, while others like Nutrition keys are now under fire for being unscientific and violating 'several key requirements for an effective approach' (6). In Europe, other front-of-pack labelling systems exist in several member states (see figure). The "traffic light system" implemented in the UK (7) uses red, orange and green symbols to indicate levels of salt, fat and other nutrients. This system has been much debated during the negotiations of the new EU legislation but the plans for an EU-wide traffic light system were eventually rejected by the European Parliament last year. The Keyhole symbol (8) has been used voluntarily in Sweden since 1989, and has also been extended to Denmark and Norway. Foods labelled with the keyhole symbol contain less fat, sugars and salt and more dietary fibre than food products of the same type not carrying the symbol, making it easier for the Nordic consumers to choose healthier food products. The international Choices Programme (9) is yet another example of front-of-pack labelling that has been adopted by several companies and has been successfully introduced in the Netherlands and other countries. Both the Keyhole and the Choices symbols are simple, easily recognisable and emphasise a healthy or healthier choice without highlighting any negative aspects in that choice. Opponents of these systems alert to the fact that, for example, processed foods carrying such stamps are not necessarily of high nutritional quality. The British traffic light system does highlight negative nutritional aspects of foods. For example, a red traffic light means the food contains a high level of one of the key ingredients fat, sugar and salt. But also in this case a collection of green traffic lights is not always a synonym of high nutritional value; one of the most cited examples is the comparison between a "Cola Light" (green light for sugars as it is made with sweeteners) and natural fruit juice (that given its natural sugar content would get a red light despite no added sugars or artificial sweeteners).
Adding to the information pitfalls of these labelling schemes, the food industry has also raised other concerns against FOP labelling. It is a controversial topic and there are both advantages and advantages on having or and not having FOP labelling and to as well as to every FOP labelling scheme. A good information system should enable consumers to make healthy selections more easily and importantly, should further encourage the food and drink industry to improve their products. Front-of-pack labelling programmes could also be used to promote sustainable and environment friendly food choices, e.g. by displaying carbon footprint labels (10).
In conclusion, the next three years will bring about important and welcome changes in the labelling of foodstuff but the food labelling discussions are likely to continue. Issues such trans fats labelling, extension of country of origin labelling to other products and FOP labelling schemes are still on the table. Further research and objective assessments of these measures are essential and will provide an invaluable source of information to guide future evidence-based proposals for the benefit of the consumer and the environment. (SC)
*Trans fats are mainly introduced in the diet through vegetable shortenings, some margarines, crackers, cookies, snack foods, and other foods made with or fried in partially hydrogenated oils and they are thought to increase risk for developing heart disease (11).
Photo: Examples of labelling schemes: A. Keyhole logo, B. Choices Logo, C. Traffic Light System example
4. SEC(2008) 92
Nutrition Research Highlights is a bi-monthly publication prepared by the Nutrition & Health Group of the DG-Joint Research Centre, Institute for Health and Consumer Protection. The Nutrition team is comprised of Sandra Caldeira, Petros Maragkoudakis & Jan Wollgast.
The views expressed here do not necessarily reflect the opinion of the European Commission.
© European Union, 2011. Reproduction of articles (excluding photographs) is authorised, except for commercial purposes, provided that the source is mentioned.