Cooking at home rather than eating out won't only save you money -- it will help keep your waist in check, too. A new paper from the University of Washington's School of Public Health shows that people who cook at home more often are likely to have a healthier diet for less cost.
Back when I was in high school, my grandma would sometimes come by to visit (read: make sure me and my brothers wouldn't destroy everything while my folks were at work) and she'd cook for us. Which was awesome, because her food was like a hot slice of heaven. She had a habit of not letting us know before-hand however, and many a day when we returned home, burgers in hand or half-stuffed into our mouths, ended up with a stern lecture best summed up as "fast food very bad, home cooked very good" -- which was usually administered in front of a steaming bowl of stew, so we didn't much mind.
Cook it yourself
Now I'm starting to suspect that she may have secretly been pursuing a career in science, as researchers from the UoW have reached the same conclusion as her. By following the dietary habits of people in the US via interviews, the team found that home cooked meals provide a healthier diet than take-out, without any extra cost.
"By cooking more often at home, you have a better diet at no significant cost increase, while if you go out more, you have a less healthy diet at a higher cost," said Adam Drewnowski, director of the UW's Center for Public Health Nutrition and first author of the paper.
For the study (part of the Seattle Obesity Study) the team interviewed 437 adults from King County, asking them to remember how eating habits (eating in and eating out) during the last week. The researchers also asked them to fill a questionnaire with detailed sections on what they ate and where.
The tool researchers use to estimate how healthy someone's diet is is known as the Healthy Eating Index. It's a kind of scale that estimates whether someone is getting proper nutrition (through the right combination of foodstuffs) or not. By comparing the participants' responses to the HEI, the team found that home-cooked food was associated with a "greater dietary compliance" -- meaning diets which included more home meals met more of the federal guidelines for a healthy diet. Chowing down on home-cooked meals three times per week raised the HEI score to about 67 points, while those who ate an average of six home meals a week had a score of about 74 points.
"The differences were significant, even with a relatively small study sample," said Drewnowski.
Better bang for your (fewer) bucks
One finding that surprised the team was that their results showed no increase in cost for the healthier diet compared to eating out. Home cooked meals were strongly associated with diets lower in sugar, fats, and overall calorie levels, but not with an increase in monthly food expenses ($330/month among low home-cooking group to $273/month among high cooking group), but rather a decrease ($261 in low eating out group vs $364 among high eating out group). A shift towards more home meals could form the basis for a more sustainable nutritional model, the team adds, while also sparing your wallet.
Drewnowski, also a professor of epidemiology at the university, realizes that although the benefits are pretty high, those who wish to eat at home more don't necessarily have the possibility to do so. People in the US suffer from what some epidemiologists call "time poverty," and take-out has the undeniable advantage of being time-efficient. Roughly half of all food expenses in the United States are spent on eating out or take-out, suggesting that a large part of the population either doesn't have the time to cook at home, or just finds it more convenient to eat out.
Another important finding was that a lower income or education doesn't lead to poorer dietary choices. The 437 participants were chosen formed a stratified random sample, and the team found no link between income or education levels and the likelihood of eating more at home or out.
"People have the preconception that a lower income leads to eating more fast foods, but that was not true in our study," Drewnowski said.
So what did make people more likely to cook? Well, households that cooked at home more often were associated with larger families, especially more children under the age of 12, marriage, or unemployment.
One of the limitations of the study (apart from the relatively small sample) was that it relied on people remembering and then self-reporting everything they ate in the past week -- and it's likely the data isn't always exact. But that's a common issue in the field of nutritional research, as Drewnowski pointed out that almost all work is done with self-reported information.
Drewnowski also said that he's going to share the findings with his students in Nutrition 303 as soon as possible, as one of the students' assignments is to estimate the price of their typical dinner. Especially the fact that healthier doesn't mean more expensive, since he's currently seeing "a lot of ramen" in their homework papers. Finally, he concludes that campaigns to promote home-cooking should go hand-in-hand with measures to encourage retailers and restaurants to sell healthier, less expensive prepared courses to merge the home-cooked meal's benefits with the comfort of take-out.
The full paper "Cooking at home: A strategy to comply with U.S. dietary guidelines at no extra cost," has been published in the American Journal of Preventive Medicine.