"Researchers say recipes from Jamie Oliver and Nigella Lawson contain more calories and fat than meals from supermarkets," The Guardian reports.
The news is based on a study that compared the nutritional content of 100 main ready meals from three leading supermarket chains and 100 recipes for main meals in bestselling books by TV chefs.
It found that recipes by TV chefs were less healthy than ready meals, containing significantly more energy, protein, fat and saturated fat, and less fibre per portion than the ready meals.
However, this study has a number of limitations.
For example, the way that the recipes and ready meals were selected could have skewed the results. The recipes were in books in the bestseller list just before Christmas, and the researchers report that the nutritional content of recipes varied between books.
Also, the criteria used to select 'main meals' could have meant that nutritional content from accompaniments could have been excluded.
And the analysis did not examine the micronutrient content (for example the vitamins and minerals) of ready meals or recipes..
Finally, it is difficult to estimate what, if any, public health impact these types of cookbooks have. We know that ready meals are a booming business (with a turnover of around £2.5 billion a year in the UK). But there is no available evidence on whether bestselling TV chef cookbooks have a significant effect on the public’s eating habits.
It is also worth noting that the study in fact concluded that neither recipes created by television chefs nor ready meals complied with nutritional recommendations. So this study doesn’t really give the green light to ready meals either.
Where did the story come from?
The study was carried out by researchers from NHS Tees and Fuse, a UK Clinical Research Collaboration (UKCRC) centre for Translational Research in Public Health, part of Newcastle University.
It was funded by Fuse, which receives support from the British Heart Foundation, Cancer Research UK, the Economic and Social Research Council and the National Institute for Health Research.
The study was published in the peer-reviewed British Medical Journal (BMJ). This article was open access, meaning that it is available for free.
The article was part of the BMJ’s Christmas coverage, which tends to be a bit more 'tongue-in-cheek' than their standard fare.
The story was covered widely by both print media and internet news sources. Coverage of the research findings was generally accurate, although the Daily Mail confused calories and kilojoules (a different unit of energy). The limitations of the study were not discussed.
What kind of research was this?
This was a cross sectional study that compared and analysed the energy, protein, carbohydrate, sugar, salt, fat, saturated fat and fibre content of 100 recipes present in bestselling books by television chefs and 100 ready meals sold by Tesco, Asda and Sainsbury’s.
The researchers tried to only include 'main courses' – i.e. they tried to exclude anything that could be a snack, side dish, starter or dessert. They also excluded breakfast dishes.
The UK government and NHS Choices both claim that ready meals are less healthy than meals cooked from scratch, and that they should not be eaten frequently.
However, the authors of this study report that the nutritional content of either ready meals or recipes by TV chefs had not been comprehensively analysed in terms of how they match up to national and international recommendations on nutrition.
For the purpose of the study, ready meals were defined as pre-prepared main courses that could be reheated in their containers and that took less than 15 minutes, including heating, to prepare.
What did the research involve?
The nutritional content of 100 recipes for main meals by TV chefs and 100 ready main meals was analysed. Meals were included if:
- they were designed to be eaten hot
- they were not described as being suitable for special occasions only
- they were not designed for breakfast
- they were not soup
- they included items from at least two of the eatwell groups of the Food Standards Agency (FSA) (fruit and vegetables; potatoes, bread, rice, pasta or other starchy food; milk and dairy foods; meat, fish, eggs, beans and other non-dairy sources of protein; foods and drinks high in fat and/or sugar)
- the recommended serving size was at least 225g (to exclude side dishes or starters)
One hundred recipes by television chefs were randomly selected. Recipes were taken from the top five bestselling books on December 20 2010 and which stated on the cover that they were tied to a television series and were by a single chef.
The books selected were:
- 30 Minute Meals and Ministry of Food by Jamie Oliver
- Baking Made Easy by Lorraine Pascale
- Kitchen by Nigella Lawson
- River Cottage Every Day by Hugh Fearnley-Whittingstall
One hundred own-brand ready meals were randomly selected from the three largest supermarket chains in the country: Tesco, Asda and Sainsbury’s.
The researchers calculated the nutritional content of the TV chefs’ recipes from the raw ingredients, excluding optional ingredients. They did this using WinDiets software, which is a suite of tools based on US and UK nutrition databases.
The nutritional content of ready meals was taken from supermarket websites.
The content per serving was then calculated using the lower end of the recommended number of servings (for example if a recipe or ready meal stated that it served four to six people, it was taken to include four servings).
What were the basic results?
The researchers found that:
- The TV chefs’ recipes contained significantly more energy, protein, fat and saturated fat than ready meals per portion. The recipes also included significantly less fibre.
- However, the recipes contained less salt than the ready meals.
- No recipe or ready meal met all of the WHO nutrient intake goals for preventing diet-related chronic diseases. However, more ready meals than recipes met the WHO goals for fibre density, and percentage of energy derived from carbohydrate and fat. Also, more ready meals exceeded the recommended amount of salt. However, these guidelines were not designed to address the nutritional content of individual meals.
If FSA 'traffic light' labelling criteria were applied, the average TV chef recipe would be:
- high in fat (red)
- high in saturated fat (red)
- low in sugar (green)
- low in salt (green)
The average ready meal would be:
- medium in fat (amber)
- high in saturated fat (red)
- low in sugar (green)
- medium in salt (amber)
How did the researchers interpret the results?
The researchers concluded that “neither recipes created by television chefs nor ready meals sold by three of the leading UK supermarkets complied with WHO recommendations. Recipes were less healthy than ready meals, containing significantly more energy, protein, fat and saturated fat, and less fibre per portion than the ready meals”. They also advise that “maximum nutritional benefit is likely to be derived from home cooking of nutritionally balanced recipes primarily using raw ingredients, rather than relying on ready meals or recipes by television chefs”.
This study has found that, based on a random sample of ready meals from three leading supermarkets and recipes from five bestselling books linked to TV series, ready meals are slightly healthier than recipes from TV chefs.
However, this study has a number of shortcomings, some of which were noted by the researchers. For example:
- The books chosen were all bestsellers in the run-up to Christmas, which may have influenced the selection of recipes.
- In the UK, the published nutritional data used for the analysis of ready meals is permitted by law to vary from 20% from the true macronutrient values.
- The addition of salt to recipes was often excluded as it was an optional ingredient, and no adjustment could be made to account for the addition of salt to ready meals before eating them.
In addition, the analysis did not examine the micronutrient content (for example the vitamins and minerals) of ready meals or recipes or the presence of artificial preservatives, flavours, colourings or stabilisers.
The authors also note that the nutritional content of recipes varied substantially between individual recipe books.
It also seems likely that many of the recipes present in the recipe books would not have met the inclusion criteria if they described, for example, a main dish and accompaniments separately, particularly if the main dish only included one class of ingredient, for example a meat dish. Only 40 of the 192 recipes in River Cottage Every Day and 43 of the 154 recipes in Ministry of Food met the researchers' inclusion criteria.
In one book, Baking Made Easy, only 13 recipes met the inclusion criteria. If the main dish did meet the inclusion criteria, it may also have skewed the results, because by not including the accompaniments it is likely that a lot of the vegetables were excluded. This may also have been a problem in the selection of the ready meals from supermarkets.
Therefore, although this study has found that ready meals are slightly healthier than recipes by TV chefs, as we can’t tell how people are actually using recipes or consuming ready meals, it is difficult to comment on how healthy they are.
As with many things we discuss in Behind the Headlines the most sensible advice would be 'everything in moderation'. Cooking your favourite recipe as a treat for a loved one once a week probably won’t harm your health significantly, nor will microwaving the occasional ready meal.
You just need to remember the fundamentals of a healthy diet – eat a low-fat diet that includes lots of fibre, such as wholegrain rice, bread and pasta, and plenty of fruit and vegetables (at least five portions a day). Read more about healthy eating.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
The Guardian, 17 December 2012
Daily Mail, 17 December 2012
The Independent, 17 December 2012
Channel 4 News, 17 December 2012
Links to the science
BMJ. Published online December 17 2012