A gentle nudge in the right direction is sometimes all people need. In this case, new research in the INFORMS journal Marketing Science finds it works when it comes to promoting healthy eating.

The study, "Which Healthy Eating Nudges Work Best? A Meta-Analysis of Field Experiments," conducted by Romain Cadario of the IÉSEG School of Management in Paris, France, and Pierre Chandon of INSEAD, have found the most effective "nudge" that bolsters healthy eating focuses on changing peoples' behavior.

The researchers looked at 96 studies that tested various methods focusing on improving food choices and eating habits.

They lumped the different methods into seven categories: 1) descriptive nutritional labeling provides calorie counts and other nutritional information on food packages or menus; 2) evaluative nutritional labeling uses pictures or graphics to help people see which choices are best; 3) visibility enhancements change the placements of healthy foods so people notice them; 4) hedonic enhancements make healthy selections more appealing in product descriptions; 5) healthy eating calls encourage people to make better choices using signage or stickers; 6) convenience enhancements make it easier to make good choices by having vegetables pre-cut or easy to grab and go; and 7) size enhancements change the portions of meals so there are more healthy foods and less unhealthy foods.

Researchers say behavioral-oriented nudges are most successful, more specifically, size enhancements appear to be the best way to improve eating habits.

"These different categories appeal to people in different ways. Some appeal to people's voice of reason or judgment, others play on their emotions and some focus directly on changing behavior," said Cadario. "By choosing the best strategy you can see results that are six-times more effective."