Diet Nudges Enable Greater Receptiveness to the Weight Loss Talk

Researchers focus on seven healthy eating strategies available to clinicians to make your next discussion about body weight to be more productive and constructive, drawn from results of a meta-analysis.

with Romain Cadario, PhD, and Caroline Apovian, MD

Endocrinologists, internists, and primary care practitioners may have different approaches to devising treatment plans and making medication choices, but there is one task most clinicians face with equal trepidation: talking to patients about weight loss.

While addressing the impact of excessive weight on the risk and severity of chronic diseases remains exigent, even among patients without obesity, it is easier said than done. This remains a tall order even as most individuals would benefit from some guidance in weight management.  

Man selecting fruit

Unhealthy eating patterns represent the leading risk factor in cardiovascular disease and type 2 diabetes, whatever a patient's weight.1-3  This urgency to find an effective way to help patients adopt better eating habits is now irrefutable given findings from the Da Qing Diabetes Prevention Outcome Study.4

Experts view this as a game changer—confirming lifestyle interventions such as diet and exercise as effective even beyond prevention of diabetes by extending to significant reductions in CVD events, microvascular outcomes, and all-cause deaths, over the long-term.

The 30-year follow-up trial evaluated patients with impaired glucose tolerance (ie, prediabetes), such that the findings reinforces and strengthens the lifestyle efficacy first demonstrated by results of the Diabetes Prevention Program Randomized Trial.5

To date, one effective approach to promote weight loss has been to employ economic means—disincentives (ie, soda tax) or incentives (ie, reduced healthcare premiums, cash) —or attempts at nutrition education to improve health habits.6-7 While useful in the general population, these methods are not conducive to a face-to-face conversation with patients during an office visit.

Food-Related Nudges Offer a Safe Way to Discuss Diet

Yet, there is an innovative way for physicians to actively assist patients without the dread, getting frustrated, or inducing tension when having to address weight loss at the next office visit. This method is called nudge interventions or healthy eating nudges.8

That's right, nudge. Don’t preach. Don’t instruct. Don’t insist. Don’t try to motivate with fear.  

Romain Cadario, PhD, visiting assistant professor of marketing at Boston University in Massachusetts, and his colleague, Pierre Chandon, a researcher at INSEAD in Fontainebleau, France, conducted an ambitious meta-analysis of field experiments in cafeteria and grocery stores, focusing on the seven most constructive “nudges” or facilitations by type and then evaluating how effective they were.8 Dr. Cadario did the research while at the IESEG School of Management in Paris, France.

In the trials evaluated as part of this review of the literature,8 ''the people were not aware that they were participating in a study," Dr. Cadario told EndocrineWeb. For instance, ''the lunch lady asks if you might cut down on the portion size today [as part of a study]."

And, while the nudges used in these studies were set in place by the individual investigators,8 Dr. Cadario believes healthcare providers and patients will be able to apply the findings, adapting the seven effective strategies to more closely fit individual patient’s eating habits.

Identifying Effective Messages for Weight Loss

As the term implies, a nudge has been defined as ''any aspect of the choice architecture that alters people's behavior in a predictable way'' but without forbidding any options or substantially changing their economic status.9

If fruit is placed at eye level, taking the space of the usual sugary cereal, for example, this is considered a nudge; conversely, a ban on junk food is not considered a nudge.

Healthy eating nudges encompass a variety of food modifications—all simple, inexpensive, and preserving freedom of choice, Dr. Caderio said, which makes them applicable to every type of patient.

These nudges, according to the researchers,8 were further categorized as:

  • Cognitively-oriented such as nutrition labeling, or similar grocery shopping indicators such as red for foods to avoid/yellow for some time foods.
  • Affectively-oriented (who wouldn't rather eat "dynamite beets" than plain beets) includes reminder texts and calls with personalized eating tips.
  • Behaviorally-oriented ("grab a healthy bite"); the effect size of each bite down to the calories saved, as well as increasing the plate size for salads, and decreasing plate size for pasta or meat meals.

Categorizing, Describing Effective Diet-Focused Nudges  

Nudges are most effective when they take aim at improvements in food choices to move toward healthy eating as a target and replacing unhealthy behaviors. The seven nudges,8 with their category and examples, to be incorporated into clinical practice are:

1. Descriptive labeling of nutrition. This strategy—which is cognitive—offers healthy eating tips that encourage the patient to use the food label to inform food choices, focusing on the calorie count, or levels of sugar, sodium, fiber, or other nutrition facts, which ever factor is more problematic for the individual. 

2. Evaluative nutrition labeling. This nudge, also cognitive, targets whole foods as more healthy or less unhealthy. Many grocery stores have food systems that help guide patients at point of purchase. For example, green stickers give the go-ahead for healthy options, red urge caution to reconsider unhealthier choices.

By pointing these aids out, patients can seek out supermarkets that offer these guides to support their efforts.

3. Visibility enhancement. This cognitive approach works at the personal level, where you might suggest that the patient use luncheon size plates for lunch and dinner, and place fruit and vegetables eye level in the fridge so they are the first items seen, and most accessible. Also, putting food temptations (in the house for other family members) away, hidden, since out of sight is out of mind.
It is also hoped that this strategy will become more widely employed in eating situations outside the home so healthier options are more visible—such as placing them first on a menu, and at eye level on store shelves.

4. Hedonic enhancements. An affective strategy is one that enhances the appeal: it is all in the name. For example, labeling beets as ''dynamite beets" to create intrigue or interest as does the use of packaging with attractive photos that grab attention.

5. Healthy eating calls. This involves a written or oral nudge that is personalized to direct the person to make a healthier food choice—this is another affective strategy. A daily text may be sent in the early evening that offers suggestions for lunch preparation for the next day– "Make a fresh choice. Have a salad," or a reminder to reach for a seltzer or tea after 7 pm. Or, to reduce unhealthy eating, a message might ask if you might share 1 dessert with everyone at the table, or to take an evening walk to ward off thoughts of food.

6. Convenience enhancements. This behavioral strategy might include reminders to reach for healthy ''grab and go" foods or to proportioned servings.

7. Size enhancements. Another behavioral strategy, this approach may employ  suggestions such as getting a presectioned plate so the largest spot is filled with vegetables and the smaller sections are filled with protein and fruit or a starch. Similarly, the nudge to use luncheon size plates for meals so the eye feels as satisfied as the stomach.

Weight Loss Focused Nudges: How Effective Are They Really?

The researchers calculated the effect size with a binary outcome—using the number of people who chose a healthy option, and then computing the long odds ratio or by simply obtaining the outcome results directly from the study, as available.8 Dr. Caderio said they used other measures, such as calculating separate effect sizes for each food when the results of a study reported data separately for each food. “Overall, the average effect size of the nudges was small,” he said.

In the end, they analyzed 299 effect sizes from among 90 articles and 96 field experiments; the studies, mostly based in in the US, included both children and adults.8

Next, they computed the daily energy equivalent expected from each effect size. In addition, they set the standard deviation for daily energy intake at 537 calories per adult; the average effect size translated to about a 124 kcal change in daily intake, or about 7.2% less than an average 1,727 calorie intake. That translates to, for example, a teaspoon of sugar contains 16 kcal, which is equal to about 8 fewer teaspoons of sugar a day.8

Changes Based on Types of Nudges: Cognitive, Affective, Behavioral

Based on the types of interventions employed,8 the researchers found:

  • Cognitive strategies reduced daily intake by 64 kcal, energy intake by 3.7%, and reduced sugar intake by 4 teaspoons daily.
  • Affective type suggestions reduced daily calories by 129 kcals, reduced energy intake by 7.5%, and reduced sugar consumption by 8.1 teaspoons.
  • Behavioral nudges lead to a reduction in 209 kcal, lowered energy intake by 12.1%, and reduced teaspoons of sugar by 13.1.

Other findings of interest: Reducing unhealthy eating proved to induce a stronger change than increasing healthy eating,8 according to Dr. Caderio. Also, he said: “there was a 30% stronger effect in reducing unhealthy fare than increasing healthy options.”

The analysis also reflected that the best interventions were observed in individuals who eat meals outside the house—in restaurants or at cafeteria—than nudges examined in grocery store studies. “That might be because eating out involved immediate consumption, but grocery shopping did not,” said Dr. Caderio.

Employing Behavioral Nudges Can Be Most Effective

"This is a great read," said Caroline Apovian, MD, FACE, FACN, professor of medicine and pediatrics at the Boston University School of Medicine and director of the Center for Nutrition and Weight Management at Boston Medical Center who was not involved in the research and so reviewed the paper for EndocrineWeb. “I use this “nudge” approach with my patients,” she said.

"Even though this is a meta-analysis," Dr. Apovian said, "the report offers a good educational piece introducing the concept of nudges, and which work best, to benefit many more clinicians."

"In employing this approach with my patients, I have found that the behavioral nudges are most effective," she said. That is—"I will suggest they do not bring the chocolate cake into the house as their default because if it is in the refrigerator, chances are fairly certain they will eat it."

Nudge Offer Safe Approch to Weight Management 

While results of the meta-analysis will not predict individual success, as researchers recently wrote in Obesity Canada, success, of course, will vary for every person given differences both in their readiness and capacity to embrace long-term weight management.10

Clinicians may begin by defining favorable results in terms of better quality of life, more self-esteem, higher levels of energy, improved overall health, prevention of further weight gain, and thinking not of ideal weight but rather in a better weight range—given the circumstances of each patient.10

‘It is not possible,” Dr. Cadario said, “to say which nudges are most applicable to try with which patients, as it will depend upon their health conditions, such as diabetes, heart disease, or thyroid issues—and there is not data on that.”  

However, he said: "The most important finding of our research is the issue of focusing on convenience. We need to make it easy for patients to eat healthy." That means directly them to preportioned, presliced foods, he said, and paying greater attention to portion sizes as most people do not realize what is reasonable and how much more they are eating then is really needed.

Another point, said Dr. Cadario, “the category of affective nudges or ''feeling" nudges is not directly targeted to changing behavior but to paying greater attention to the pleasure of eating.” This may matter much more to some patients, then others, so he recommends encouraging you to suggest they do as the French do—put more focus on the pleasure of eating, and less so on the quantity.

"If you want to eat healthy, you have to find some pleasure in it," he said, perhaps from personal experience. "If someone is only eating for health, they may be sacrificing pleasure so they care less about their health. Focusing on restraint may make them healthier—but not very happy."

Neither Dr. Apovian nor Dr. Cadario had any financial conflicts with regard to this study.

Continue Reading:
Nuanced Approach More Likely to Achieve Effective Weight Management
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