We’ve heard it again and again: Cooking at home is the healthier choice. Right? Actually, it may be pretty wrong. Recent research out of the UK suggests that sometimes, that may not be the case. So depending on what cookbook you’re using, it may be time to shelve it for a little while. Here’s why.

What’s The Deal? – Watch Those Calories

Cooking Pot Photo: Nicole Abalde

Whether it’s from a magazine, the government, or great-Grandma, advice about improving healthy eating habits usually points to home cooking as the answer. Eating away from home has been linked with diets higher in calories and lower in micronutrients such as iron, calcium, and vitamin CEating out of home and its correlates in 10 European Countries. Orfanos P., Naska A., Trichopolos D., et al. Department of Hygiene and Epidemiology, University of Athens Medical School, Athens, Greece. Public Health Nutrition, 2007 Dec; 10(12): 1515-25. Eating out of home and its association with dietary intake: a systematic review of the evidence. Lachat C., Nego E., Verstraeten R., et al. Nutrition and Child Health Unit, Institute of Tropical Medicine, Antwerp, Belgium. Obesity Reviews, 2012 Apr; 13(4):329-46..

Findings from recent studies, however, suggest cooking at home may not always be the better option. A group of British researchers compared the nutritional profiles of “home-cooked” meals created by celebrity chefs to those of prepared meals sold in local supermarketsNutritional content of supermarket ready meals and recipes by television chefs in the United Kingdom: cross sectional study. Howard S., Adams J., White M. NHS Tees, Stockton on Tees, UK. British Medical Journal, 2012 Dec; 345: e7607.. The study compared 100 supermarket meals with 100 main meal recipes (with items from two or more food groups) created by UK-based TV chefs. The prepared meals were randomly chosen store-brands from the three biggest grocery chains in the UK. The items had to be main-dish meals, come in containers used for both heating and serving, and be ready to eat in fifteen minutes or less. (Think microwavable TV dinners.)

The 100 chef-created recipes came from Amazon UK’s December list of the top five bestselling cookbooks with a TV series tie-in on the cover, featured a single chef, and included main-dish recipes. The five lucky books? “30 Minute Meals” by Jamie Oliver, “Baking Made Easy” by Lorraine Pascale, “Ministry of Food” by Jamie Oliver, “Kitchen” by Nigella Lawson, and “River Cottage Everyday” by Hugh Fearnley-Whittingstall. The researchers compiled a random selection of meal recipes from these cookbooks for the study. Both the TV dinners and chef recipes were meant to be served as a main dish.

Looking at the nutritional content (total calories, protein, carbohydrates, sugar, sodium, fat, saturated fat, and fiber) of the recipes and meals, researchers tried to answer a simple question: Is one type of meal or the other healthier? They used the World Health Organization’s (WHO) dietary guidelines and the British Food Standards Agency (FSA) guidelines as nutritional standards for comparison. (The WHO guidelines are similar to the USDA Guidelines; both aim to promote health and reduce risk for chronic disease.) Although the two sets of guidelines differ a bit, both give the breakdown of calorie percentages that should come from fat, protein, and carbohydrates. They also set daily limits on salt, cholesterol, and saturated fat, though it’s important to remember some healthy diets can vary from these recommendations.

The results were pretty surprising. Not a single ready meal or recipe met all of the WHO guidelines Nutritional content of supermarket ready meals and recipes by television chefs in the United Kingdom: cross sectional study. Howard S., Adams J., White M. NHS Tees, Stockton on Tees, UK. British Medical Journal, 2012 Dec; 345: e7607.. And the chef-created recipes appeared to be less healthy than the store-bought meals: They were typically higher in calories and lower in fiber. In sodium, however, the chefs’ meals fared a bit better than ready meals, meeting the FSA guideline of less than 0.6 grams of sodium per 100 grams of food. Now, it’s worth keeping in mind — as the researchers mention at the end of their report — that these WHO standards are based on average intake over time rather than individual meals. However, the researchers chose to use the WHO standards because of the lack of other international criteria on which to base their study.

It’s not the only study to report these results: Another group of researchers found 87 percent of recipes from popular British chefs don’t measure up to FSA guidelines.

Why it Matters — A Recipe for Disaster?

Some researchers argue celebrity chefs can have considerable influence on audiences’ food choices and could be contributing to Britain’s obesity epidemic. If that’s true, it’s certainly possible the same could be true in other countries, including the U.S. Sky-high obesity rates — 26.1 percent of adults in England and 35.7 percent of adults in the US — present a huge challenge for public health. Obesity increases the risk for all sorts of chronic diseases, including heart disease and diabetesWhy does obesity increase the risk for cardiovascular disease? Boden G., Salehi S. Temple University Hospital, Philadelphia, Pennsylvania. Current Pharmaceutical Design, 2013 Feb 20.. And eating more energy-dense foods such as fast food and restaurant meals has been linked to higher body fat, which can also lead to similar problemsDietary strategies for weight management. Rolls, B. J. Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA. Nestle Nutrition Institute Workshop Series, 2012; 73: 37-48.Dietary determinants of energy intake and weight regulation in healthy adults. McCrory M. A., Fuss P. J., Saltzman E., et. al. Energy Metabolism Laboratory, Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA. The Journal of Nutrition, 2000 Feb; 130(2S Suppl): 276S-279S..

So is the freezer aisle or restaurant the only option left for dinner? No way. Take these study results with a grain of salt (but watch those sodium limits!) and don’t throw out the cookbooks just yet. While some research does show recipes from top TV chefs might lean toward unhealthy, this doesn’t hold true for all recipes and cookbooks. And just because ready meals appear to be healthier in some respects does not mean they are nutritional superstars. Vitamins, minerals, and additives weren’t considered in the study’s evaluation, so the nutritional picture presented isn’t so completeNutritional content of supermarket ready meals and recipes by television chefs in the United Kingdom: cross sectional study. Howard S., Adams J., White M. NHS Tees, Stockton on Tees, UK. British Medical Journal, 2012 Dec; 345: e7607.. And going out for dinner every night is probably isn’t the answer: Other research has linked eating away from home with higher calorie and fat intake, and lower micronutrient consumptionEating out of home and its association with dietary intake: a systematic review of the evidence. Lachat C., Nego E., Verstraeten R., et al. Nutrition and Child Health Unit, Institute of Tropical Medicine, Antwerp, Belgium. Obesity Reviews, 2012 Apr; 13(4):329-46..

The Takeaway — Conscious Cooking

Don’t be fooled: Prepared meals are not always healthier than what you may cook at home. But the surrounding research does bring to light an important point. Cooking at homecan be healthier, but it isn’t automatically so.

Keep an eye on portion size and ingredients — not on the Food Network. And don’t forget to take a look at Greatist’s healthy recipe collection!

Are TV chefs promoting unhealthy eating, or should we treat their recipes more like restaurant meals? Share with us in the comments below, or tweet our Health Editor @ksmorin!