Climate change poses unprecedented global challenges for the living beings and living systems of this planet. The risks to human health, public health, and the natural environment are numerous and include major disruptions to social and economic systems ( 1– 5). Likewise, climate change is an overarching social justice and human rights issue ( 6, 7). The negative consequences of climate change are projected to increase in severity ( 8). While greenhouse gas emissions continue to climb, scientists advocate the urgency of reducing emissions along with the associated carbon storage to restore and balance the global climate system – with the additional goal of minimizing irreversible climate change ( 1, 9, 10).
A burgeoning array of interdisciplinary data implicates food from animal sources in greenhouse gas emissions, increased resource consumption, and environmental degradation ( 11– 26). Ruminants, particularly beef cattle, demonstrate greater environmental burdens than other animals ( 18, 20, 27, 28). Other studies indicate that plant-based diets and reducing animal product consumption are effective options in ameliorating environmental degradation, decreasing greenhouse gas emissions, and minimizing resource consumption ( 11– 28). Attaining climate mitigation targets may not be possible without reductions in animal product consumption ( 29, 30). Additionally, the Academy of Nutrition and Dietetics recognizes that well-planned plant-based diets are nutritionally sound throughout the entire lifecycle ( 31), and are associated with reduced chronic disease morbidity and mortality ( 25, 32, 33).
There is a growing body of literature regarding concern for climate change among allied health and public health providers. In their survey of United States public health nurses ( n = 786), Polivka and colleagues found that 75% of respondents agreed that humans are severely abusing the environment ( 34). Half of the respondents agreed that their nursing department had an obligation to address the health impacts of climate change ( 34). Most disagreed with the statement that their nursing division was prepared to address the health-related impacts of climate change ( 34). Truckner surveyed health care providers who were members of the Wilderness Medical Society concerning awareness and beliefs about human-induced environmental degradation (HIED) ( 35). Of the 658 respondents, 86% were physicians involved in emergency and primary care medicine while one respondent was a registered dietitian ( 35). Eighty percent of respondents believed that HIED had directly and adversely affected patients, but 93% reported that they do not distribute information about the adverse health effects of HIED to patients ( 35). A recent survey of African-American physicians with 284 respondents found that while 88% of respondents agree that climate change is directly relevant to patient care, 71% of respondents do not know how to approach the issue with patients ( 36). Finally, in a survey of local public health department directors in the United States ( n = 217), 34% report that they have programs to increase the consumption of local, organic, and plant-based foods, while 54% do not have and/or are not planning to address the role of food in climate change mitigation activities ( 37).
Registered dietitians are well positioned to educate patients, the public, allied healthcare providers, and interdisciplinary colleagues about food choices that can minimize environmental degradation. With a unique skill set that is applied across a variety of settings and institutions, dietitians can take a major leadership role in promoting diet-related climate change mitigation actions while capitalizing on the health benefits of promoting plant-based diets for chronic disease prevention and amelioration ( 18, 22, 38, 39).
Within the dietetics profession, there has been a growing awareness of the relationship between food systems and impact on the natural environment ( 40, 41). However, it is unclear how many registered dietitians in the United States are aware of the connection between diet and climate change and take action to mitigate climate change in their professional practice. Thus, the purpose of this research study was to provide a quantitative account of registered dietitians’ beliefs and concerns about climate change; determine registered dietitians’ involvement in climate change mitigation activities; and understand if a relationship exists (if at all) among (a) practice behaviors, (b) concern for climate change, (c) personal dietary behaviors, and (d) demographic variables.
Our study sample consisted of registered dietitians credentialed by the Commission on Dietetic Registration. Along with a viable email address, these were the only inclusion criterion for this study. Our survey was approved by the Academy of Nutrition and Dietetics in January 2012. A cross-sectional survey was created for primary data collection. The survey was tested for face validity and revised accordingly. It contained 52 questions eliciting awareness, beliefs, and concern regarding diet-related climate change and environmental degradation; practice behaviors and outcomes; and personal dietary behaviors. We also captured basic demographic information. Responses included numeric, nominal, ordinal, and four pre-categorized open-ended "other" questions. These "other" questions were scrutinized for validity. Table 1 offers examples of the questions posed.
Examples of questions from the survey.
| I. Questions eliciting concern for climate change |
| To what degree do you believe that climate change is an important issue? |
| □ Strongly agree |
| □ Agree |
| □ Unsure |
| □ Disagree |
| □ Strongly disagree |
| To what degree do you believe that climate change is an important practice issue for registered dietitians? |
| □ Strongly agree |
| □ Agree |
| □ Unsure |
| □ Disagree |
| □ Strongly disagree |
| To what degree do you believe that registered dietitians should play a major role in climate change mitigation strategies? |
| □ Strongly agree |
| □ Agree |
| □ Unsure |
| □ Disagree |
| □ Strongly disagree |
| II. Questions eliciting practice behaviors |
| Do you engage in activities that promote diet as a climate change mitigation strategy? |
| □ Yes |
| □ No |
| Do you recommend organic foods in practice (when at work)? |
| □ Yes |
| □ No |
| Do you recommend locally produced foods in practice (when at work)? |
| □ Yes |
| □ No |
| III. Questions eliciting personal behaviors |
| Do you obtain food from farmers markets, community supported agriculture, and/or other locally grown sources? |
| □ Yes |
| □ No |
| Are you vegan (avoid the consumption of all animal products)? |
| □ Yes |
| □ No |
| Are you vegetarian (avoid the consumption of animal flesh including fish but may include eggs, dairy products, etc.) |
| □ Yes |
| □ No |
We investigated whether being vegetarian or vegan impacted actions to mitigate climate change due to presumed level of comfort with plant-based diets. Hence, several hypotheses were proposed at the outset of the study including: (1) The personal dietary behavior of being either vegetarian or vegan predicts the action of promoting diet as a climate change mitigation strategy among registered dietitians, (2) the belief that animal products are not essential for a healthy diet predicts the action of promoting diet as a climate change mitigation strategy among registered dietitians, and (3) comfort in promoting solely plant-based (vegan) diets predicts the action of promoting diet as a climate change mitigation strategy among registered dietitians.
A base target sample size of 383 was required from the total universe of 84,146 registered dietitians in the United States using a 5% margin of error, a 95% confidence level, and an anticipated response rate of 20%. Thus, we invited 1,915 dietitians to participate in the study. The technology team at the Academy of Nutrition and Dietetics provided the random sample from their current database of registered dietitians credentialed in the United States. The survey was completed online via the Internet-based SurveyMonkey (Palo Alto, CA, USA) research service.
An email including an explanation of the study, informed consent, and a link to the survey was sent on March 7, 2012. The ability to enter a drawing for a $100 gift card was offered to thank potential study participants for their time and efforts. Because the response rate was less than anticipated on March 21, 2012 (there were 305 responses, short of the target of n = 383), the Academy of Nutrition and Dietetics provided another random sample of 1,994 registered dietitians. The second round started on March 22, 2012 and continued for 1 week until midnight March 29, 2012. Over the two rounds, a total of 625 registered dietitians provided consent.
Approximately, 91 email addresses were returned with error messages. For data integrity purposes, duplicate IP addresses were checked against the original subject lists. Three survey responses were eliminated because those individuals were not included in the original sample. Those individuals who provided consent but did not otherwise complete any part of the survey were also eliminated.
The survey data were analyzed using SPSS version 20.0 (IBM Corporation, Armonk, NY, USA). Descriptive statistics and inferential statistics including the chi-square test for independence, the chi-square goodness of fit test, Fisher’s exact test, and logistic regression were used. There was limited knowledge of how the study participants (n = 570) differed (if at all) from those dietitians in the entire study population (3,909 potential survey participants). Therefore, the chi-square goodness of fit test was utilized to check the extent to which the distribution of the variable region (the only variable available among both groups) differed at all between all study participants and all potential survey participants. In fact, dietitians in the South participated in the study less often than expected, while more dietitians participated from the West and Midwest than anticipated, respectively. The chi-square goodness of fit test did reveal a statistically significant difference between the two groups, p = 0.0136. Therefore, it was important to further understand if this difference impacted the overall results.
The percentage of respondents holding particular views were calculated using the "population" weights (the percentage of respondents in each region in the population) rather than the sample weights (the percentage of respondents in each region within the sample). In each case, there was very little difference in the percentages. For example, 74.9% of respondents either strongly agree or agree that climate change is an important issue. When the population "weights" (proportion of the population in each region) were used, the corresponding percentage is 74.1. Similar results were obtained with other responses to other questions. This all suggests that differences between the sample and the study population are unlikely to affect the conclusions of this study.
Survey participants were free to answer the questions as desired, and thus, every question was optional as indicated in the consent form. Not all survey participants answered every question. All data analyses were based only on non-missing data. Statistical significance was achieved if the p-value was <0.05.
The response rate was 14.6% with n = 570 usable responses from 3,909 potential survey participants. Approximately 96% of survey respondents were women. Survey participants resided in all 50 states – but not the District of Columbia. One survey participant resided in Guam, while another resided in Canada. Over 92% of study participants describe themselves as White/Caucasian, followed by Asian (5%), Black/African-American (2%), American-Indian or Alaska Native (0.4%), Other/Mixed Race (0.4%), and Native Hawaiian or Other Pacific Islander (0.2%), respectively. Two percent of survey participants described their ethnicity as being Hispanic or Latino. Survey participants ranged in age from 23 to 75 years, with the mean being 42.7 years and the SD, 12.3 years. The number of years in dietetics practice ranged from 1 to 49, with a mean of 16 years and an SD of 11.6 years. The number of years of higher education obtained ranged from 4 to 20, with a mean of 5.8 years and an SD, 2.6 years. The majority of survey participants represented the practice area of clinical dietetics (55.0%), followed by Public Health (16.0%) and Education/Teaching and Research (8%).
Approximately, 75% of survey participants either strongly agree or agree that climate change is an important issue. Over 45% of survey participants either strongly agree or agree that climate change is an important practice issue for registered dietitians, while almost 50% are unsure that registered dietitians should play a major role in climate change mitigation strategies. However, 34% strongly agree or agree that registered dietitians should play a major role in climate change mitigation strategies.
Table 2 shows the results of a logistic regression analysis predicting the probability of the belief (strongly agree, agree) that climate change is an important issue based on demographic variables. For the predictor variable region of the country, the South was the reference region. The corresponding p-values of the indicator variables, West ( p = 0.003), Midwest ( p = 0.008), and Northeast ( p = 0.00005) denote that the effects of these variables are statistically significant. That is, if living in the Midwest, West, or Northeast, the odds of strongly agreeing or agreeing that climate change is an important issue is 2.1, 2.4, and 3.5 times that of those living in the South (the reference region), respectively – holding all other variables constant.
Logistic regression analyses predicting strong agreement or agreement that climate change is an important issue based on demographic variables .
| Predictor variable | p-Value | Odds ratio |
|---|---|---|
| West | 0.003 | 2.442 |
| Midwest | 0.008 | 2.128 |
| Northeast | 0.00005 | 3.537 |
| Gender | 0.922 | 0.943 |
| White/Caucasian | 0.265 | 0.581 |
| Ethnicity | 0.178 | 0.236 |
| Area of practice – clinical nutrition | 0.172 | 0.692 |
| Area of practice – public health | 0.095 | 0.560 |
| Age | 0.465 | 1.015 |
| Years of practice | 0.053 | 0.960 |
| Years of education | 0.704 | 0.982 |
| Constant | 0.044 | 17.864 |
Dietitians were divided when asked if animal products are essential for a healthy diet. Nearly 42% of survey participants either strongly disagreed or disagreed that animal products are essential for a healthy diet, while 8% are unsure. Almost 50% of survey participants either strongly agreed or agreed that animal products are essential for a healthy diet.
Next, we tested the hypothesis that the variable personal dietary behavior of whether or not vegetarian or whether or not vegan predicts the promotion of diet as a climate change mitigation strategy among registered dietitians. Of note is that more than 10% of survey participants reported being vegetarian, while 2% reported being vegan. Tables 3 and 4 show the analysis of the survey participants that engage in activities that promote diet as a climate change mitigation strategy based on the personal behaviors of being vegetarian or vegan, respectively. The corresponding p-value for both the chi-square test for independence (0.002) and the Fisher’s exact test (0.007) are exceedingly small, indicating that the results are statistically significant. These data suggest that vegetarian and vegan dietitians are significantly more likely than non-vegetarian and non-vegan dietitians to engage in activities that promote diet as a climate change mitigation strategy.
Number and percentage of survey participants that engage in activities that promote diet as a climate change mitigation strategy based upon being vegetarian a,b,c .
| Vegetarian (yes) ( n = 53) | Vegetarian (no) ( n = 341) | |
|---|---|---|
| Number and percentage that engage in activities that promote diet as a climate change mitigation strategy | 30 (56.6%) d | 162 (34.6%) |
aDifference = 22%; b95% CI = 7.0–36%; cPearson chi-square = 9.9; dp-value <0.002 .
Number and percentage of survey participants that engage in activities that promote diet as a climate change mitigation strategy based upon being vegan a,b .
| Vegan (yes) ( n = 10) | Vegetarian (no) ( n = 512) | |
|---|---|---|
| Number and percentage that engage in activities that promote diet as a climate change mitigation strategy | 8 (80%) c | 186 (36.3%) |
aDifference = 43.7%; b95% CI = 18.5–68.8%; cFisher’s exact test, p-value <0.007 .
Following this, we tested the hypothesis that the belief that animal products are not essential for a healthy diet predicts the promotion of diet as a climate change mitigation strategy. The corresponding p-value (0.013) for the number and percentage of survey participants that engage in activities that promote diet as a climate change mitigation strategy based on the belief that animal products are not essential for a healthy diet is exceedingly small, indicating that the results are statistically significant. These data suggest that those who believe that animal products are not essential for a healthy diet are significantly more likely to engage in activities that promote diet as a climate change mitigation strategy than those who do believe that animal products are essential for a healthy diet.
Lastly, we tested the hypothesis that self-efficacy (comfortable, very comfortable) in promoting solely plant-based (vegan) diets predicts involvement in diet and climate change mitigation strategies. Table 5 shows the analysis.
Number and percentage of survey participants that engage in activities that promote diet as a climate change mitigation strategy based on self-efficacy (comfortable, very comfortable) in promoting a plant-based diet a,b,c .
| Self-efficacy (yes) ( n = 193) | Self-efficacy (no) ( n = 330) | |
|---|---|---|
| Number and percentage that engage in activities that promote diet as a climate change mitigation strategy | 93 (48%) d | 101 (30.6%) |
aDifference = 17.6%; b95% CI = 8.9–26.2%; cPearson chi-square = 16.1; dp-value < 0.00005 .
The corresponding p-value (0.00005) is exceedingly small and <0.05, indicating that the results are statistically significant. These data suggest that those who report self-efficacy in promoting plant-based (vegan) diets are significantly more likely to engage in activities that promote diet as a climate change mitigation strategy than those who report that they are less comfortable in promoting plant-based diets.
To our knowledge, this is the first study to collectively understand concerns and actions to mitigate climate change among a random sample of all registered dietitians in the United States. This study yielded several important findings: (1) the majority of registered dietitians surveyed agreed that climate change is an important issue, but are largely unsure that registered dietitians should play a major role in climate change mitigation strategies; (2) the region of the country that one resides is the demographic variable that was an important predictor of the belief that climate change is an important issue; (3) being vegetarian or vegan was significantly associated with actions promoting diet as a climate change mitigation strategy; (4) the belief that animal products are not essential in the diet was significantly associated with actions promoting diet as a climate change mitigation strategy; (5) comfort in promoting solely plant-based diets was significantly associated with actions that promote diet as a climate change strategy; and (6) the gap between concern for climate change and practice behaviors suggests a lack of knowledge or self-efficacy in connecting practice behaviors to climate change mitigation.
In an era where scientists forecast the current and future dimensions of climate change as worrisome, it is reassuring that 75% of registered dietitians agree or strongly agree that climate change is an important issue. This is consistent with the majority of Americans who believe in the reality of global warming ( 42). However, only 46% of registered dietitians strongly agreed or agreed that climate change is an important practice issue and 50% are unsure if registered dietitians should play a major role in climate change mitigation strategies. This is similar to the findings of Sulda et al. in their survey of South Australian dietitians and nutritionists who ranked concern for climate change at a mean of 8.5 out of 10 with 10 being extremely important – but then ranked it lower in importance to a dietitian’s professional work in overweight and obesity, food security, diabetes, etc. ( 43). Dietary recommendations to ameliorate nutrition-related chronic diseases can offer simultaneous co-benefits to the natural environment, such as reduced greenhouse emissions, eliminating the notion of competing interests ( 18, 25, 38, 39). Thus, offering dietitians educational opportunities and experiences that increase knowledge, skills, and abilities with regard to diet-related climate change mitigation as well as the resultant co-benefits could prove to be highly beneficial.
Approximately 38% of survey participants engage in activities that promote diet as a climate change mitigation strategy. This corresponds with the 34% that strongly agreed or agreed that registered dietitians should play a major role in climate change mitigation strategies and the 45% that strongly agree or agree that climate change is an important practice-based issue. While not the majority, it is still impressive considering that only 8% reported that their respective workplace provided funding for diet and climate change mitigation activities. Nevertheless, the substantial gap between the 75% that strongly agree or agree that climate change is an important issue and the 38% that promote diet as a climate change mitigation strategy should be noted. It may be that dietitians lack the necessary education, experiences, or skills to take action ( 44, 45). Or, like the general population, it may be that climate change is seen as a distant threat ( 42). Wilson and Garcia found that clinical dietitians in Canada do not routinely discuss the impact of food choices on the natural environmental with patients ( 46). In recent years though, some dietetic internship programs in the United States have incorporated "Sustainable Food Systems" as an emphasis in their accredited training program ( 44), while some nutrition degrees from the associates level ( 47) through the graduate level ( 48) and also offer such programs that even span across departments ( 48). It will be important to learn the effect of these training programs on future dietetics-related practice behaviors and the associated environmental outcomes. Additionally, exposing students to risk-taking and diplomacy may prove fruitful ( 49). Similar to other studies of allied health and public health providers ( 34– 37), our results demonstrate that there is a need within and across health disciplines for skill in incorporating climate change mitigation into practice.
Region of the country in which a registered dietitian resided was an important predictor in strongly agreeing or agreeing that climate change is an important issue. Dietitians residing in the South were significantly less likely to strongly agree or agree that climate change is an important issue. Certainly, norms, beliefs, and attitudes may exist and persist depending on the state and region in which one resides. Moreover, media coverage of diet-related climate change issues varies in certain geographic regions, and has been under-represented altogether in the media in previous years – particularly in the South ( 50). Because of the urgent nature of climate change, further investigation of what norms enhance or detract from the importance of climate change mitigation in practice is warranted – including those that occur from within the profession itself. Qualitative research may be particularly helpful in this instance. Other useful research may include the number of dietitians employed by the livestock industry in the South compared to other regions of the country; understanding exposure (or lack thereof) to diet-related climate change mitigation in training experiences and didactic education; and even understanding attitudes about energy sector jobs in the South.
Although our level of statistical significance was articulated at the outset of the study ( p = 0.050), our logistic regression analysis found that the variable "Number of Years in Practice" approached statistical significance at 0.053. After holding all other variables constant, the odds of agreeing that climate change is an important issue negligibly declined with increasing number of years in practice. Further research is warranted to understand this trend. However, it is plausible that because climate change is a recently documented phenomenon, dietitians practicing longer may have spent less time being aware of climate change than more recently trained dietitians.
Some practice-based publications have called upon registered dietitians to take action in their professional practice and personal lives to minimize the impact on the natural environment, including increasing plant-based protein consumption ( 40, 41). Interestingly, we found a significant relationship between the personal behaviors of being vegan or vegetarian and practice outcomes, as well as comfort in promoting solely plant-based diets. These findings have important implications for dietetics education, public health practice, and continuing education. Providing knowledge, skills, and experiences to increase skill and comfort in promoting plant-based meals among registered dietitians could make a difference with regard to practice-based recommendations. Dietitians in turn can share such skills across the healthcare, agriculture, food systems, environmental health, and the public health spectrum ( 3, 18, 51). It is important also to note that dietitians were nearly divided with regard to the statement that animal products are essential for a healthy diet. Thus, understanding dietitians’ beliefs about the role of animal products and plant-based foods may be key to understanding practice-based actions to reduce impact on the natural environment.
Just over 10 percent (10.3%) of survey participants reported being vegetarian, while 2% reported being vegan. It has been estimated that over 2% of the American population is vegetarian, and just over 2% is vegan ( 52). Dietitians participating in this survey reported being vegetarian in higher percentages than the general population, while those that reported being vegan is consistent with the general population.
Additionally, it is important to point out that although general messages to eat less animal products to mitigate climate change are appropriate and constructive, substantive recommendations, and meal planning advice are also warranted. Registered dietitians proficient in plant-based dietary patterns can offer suggestions across the entire lifecycle, disease conditions, and food planning and food procurement settings. For instance, non-governmental environmental organizations that are uncomfortable offering dietary advice as a way to reduce impact on the natural environment ( 53) may find great benefit in partnering with registered dietitians.
This may be the first study to examine concerns and actions regarding climate change among a randomly selected sample of all registered dietitians credentialed in the United States. It may also be the first to quantitatively examine the relationship between the personal behaviors with regard to climate change mitigation efforts. However, this study did not query those who intentionally restrict their respective intake of animal products who may be considered semi-vegetarian or "flexetarian," which is worthy of future study. Because this was an exploratory study, further inquiry over time is necessary. It is important to note that those who completed the online survey may be different than those who did not complete the online survey. That is, they could have been a self-selected group that is more likely to be supportive of the topic than those that did not respond. Our response rate was low, and we do not know if all intended survey recipients received our email, as filters may have prevented our survey from reaching the respective dietitian’s email inbox. Furthermore, it could be that those who participated in the survey provided responses based on the nature of questions, termed social desirability bias ( 54). Lastly, further testing the reliability of our survey tool is important for future research.
Nutrition professionals are called upon to help improve planetary health. Because of their skill set and their unique role in healthcare and in all aspects of food and nutrition – registered dietitians are well positioned to become increasingly important allies in novel approaches to climate change mitigation strategies. Efforts that enable more registered dietitians to build knowledge, skills, and self-efficacy regarding diet-related climate change mitigation activities that they utilize in practice could substantially improve both public health and planetary health.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
We extend our gratitude to the dietitians who completed our survey and to the Academy of Nutrition and Dietetics (AND) that provided our random sample of all Registered Dietitians credentialed in the United States free of charge. AND had no role in the design, analysis, or writing of this article. The views expressed in this study do not represent an official position of AND, The Brookline Public Health Department, or Simmons College. Lastly, we thank all reviewers that offered suggestions that enhanced our publication.