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The Internet offers a viable platform for cost-effective and wide-reaching health interventions. However, little is known about use of the Internet to help with diet, weight, and physical activity (DWPA) using a nationally representative sample from the United States.
To (1) assess the demographic characteristics of people who use the Internet to help with DWPA, (2) assess whether usage trends changed over time, and (3) investigate the associations between using the Internet for DWPA and health behaviors.
Data on Internet users from the 2007 and 2011 iterations of the Health Information National Trends Survey (HINTS), N=4827 were analyzed using multiple logistic regression to determine the demographic correlates of using the Internet for help with DWPA. Multiple linear regression was used to test the associations between Internet use for DWPA and three health behaviors: fruit intake, vegetable intake, and physical activity.
A larger percentage of Internet users used the Internet for DWPA in 2011 (42.83%) than in 2007 (40.43%). In general, Internet users who were younger (OR 0.98,
Contrary to prior research, our population-level study did not show a pronounced gender difference in the use of the Internet for DWPA. Our results support the increasing viability of the Internet as a platform for behavior change intervention, as a growing percentage of Internet users are turning to the Internet for help with DWPA. Additionally, using the Internet for DWPA is associated with better DWPA-related health behaviors.
Poor nutrition and physical inactivity have significant and negative implications for individuals and society at large. On the individual level, poor nutrition and physical inactivity are risk factors for obesity, type 2 diabetes, and heart disease [
The demographic trends in DWPA use provide essential information to those seeking to develop, implement, and evaluate Internet-based DWPA programs. Demographic information provides a basis for tailored and targeted programs, which produce better health outcomes than nontailored or nontargeted programs (see [
Regardless of who uses Internet-based DWPA programs, the viability of the Internet as a platform for wide-reaching health behavior interventions is dependent on these programs actually reaching a large population of users. However, because no large nationally representative studies on trends in Internet use for DWPA have been conducted, it is not known whether Internet use for DWPA is increasing or decreasing. Therefore, the second aim of our study is to investigate temporal trends in usership—namely, whether a higher percentage of Internet users used the Internet for DWPA in 2011 than in 2007, and whether there are important demographic differences in usership over time. Research by the National Telecommunications and Information Administration indicates that overall use and access to the Internet is increasing; that is, more people had Internet in their homes in 2010 compared to 2007 and more people had broadband, indicating faster connection speeds [
A third aim of our study is to examine how use of the Internet for DWPA relates to adherence to DWPA-related behaviors. To date, no studies have assessed the relationship between ad libitum use of the Internet for DWPA and health behaviors in a nationally representative study. Because the viability of Internet-based programs depends on their actual association with health behaviors, we aim to examine whether use of Internet-based DWPA programs is associated with the key health behaviors of vegetable intake, fruit intake, and exercise. To investigate these relationships, we examined data from the 2007 and 2011 iterations of the US National Cancer Institute’s Health Information National Trends Survey (HINTS).
This study used data from two iterations of HINTS, administered in 2007 and 2011. HINTS is a national probability survey of US adults that assesses usage and trends in health information access and understanding. By oversampling high minority areas, HINTS provides greater precision of estimates for minority subpopulations. HINTS has been administered iteratively, and publicly accessible datasets from 2003, 2005, 2007, and 2011 are available at the HINTS website [
A total of 3582 individuals completed the mailed survey in the 2007 HINTS, and 3959 individuals completed the 2011 survey. Of all possible participants, those who had missing data on using the Internet for DWPA (32.8%) or key demographic variables (2.5%) were excluded, resulting in a sample size of 4827 in demographic analyses. Those who had data for using the Internet for DWPA but not for health behavior variables were excluded on an analysis-by-analysis basis, with the greatest missing data for physical activity (10.5%), and negligible missingness for vegetable intake (5 participants), and fruit intake (2 participants).
We used participants’ self-reports of age, sex, level of education, and height and weight. We converted height and weight to body mass index (BMI) scores in which higher scores indicate a generally less healthy weight-to-height ratio.
Participants answered one question, “In the last 12 months, have you used the Internet to: Use a website to help you with your diet, weight, or physical activity?” with a yes/no response.
Fruit and vegetable intake were each assessed with the question, “About how many cups of fruit [vegetables] (including 100% pure fruit [vegetable] juice) do you eat or drink each day?” Examples of 1 cup of fruits and vegetables were provided, such as “1 small apple” or “3 broccoli spears.” Participants had 7 response options from “none” to “4 cups or more” such that higher scores represent greater intake. Fruit and vegetable intake scores were analyzed separately.
Physical activity was assessed with the question, “In a typical week, how many days do you do any physical activity or exercise of at least moderate intensity, such as brisk walking, bicycling at a regular pace, and swimming at a regular pace?” The 8 response options ranged from “none” to “7 days per week.”
To analyze differences over time, the 2007 and 2011 datasets were combined using methods employed in prior HINTS analyses [
Multiple logistic regression was used to determine the demographic correlates of usage of the Internet for DWPA and to assess whether changes occurred in these demographic associations over time. Interaction terms between demographic variables and survey year were included in the model to identify significant changes in demographic makeup of users over time. Multiple linear regression, controlling for demographic variables, was used to analyze the strength of the relationship between use of the Internet for DWPA and the health behaviors of fruit and vegetable intake and physical activity. Interaction terms between Internet use for DWPA and survey year were added to the regressions to assess changes across time. Goodness of fit for all logistic models was assessed with the Hosmer-Lemeshow (H) test statistic and Tjur’s [
Age, sex, level of education, BMI, race/ethnicity, and marital status were examined as demographic predictors of using the Internet for DWPA. Each increase in level of education (OR 1.40, 95% CI 1.38-1.42,
Demographic correlates of using the Internet for help with DWPA in 2007 and 2011.
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Did not use Internet for DWPA | Used Internet for DWPA | |||||||
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2007 | 2011 | 2007 | 2011 | |||||
n | % | n | % | n | % | n | % | ||
Total sample |
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1462 | 59.6 | 1457 | 57.2 | 961 | 40.4 | 947 | 42.8 |
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Male | 878 | 29.9 | 630 | 29.2 | 640 | 22.7 | 309 | 19.0 |
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Female | 584 | 29.3 | 827 | 28.0 | 321 | 17.8 | 638 | 23.9 |
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Non-Hispanic white | 1108 | 47.8 | 1006 | 45.6 | 674 | 30.3 | 622 | 31.2 |
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Non-Hispanic black | 137 | 5.2 | 193 | 6.7 | 113 | 4.7 | 124 | 4.7 |
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Hispanic | 114 | 6.8 | 113 | 5.6 | 90 | 5.1 | 100 | 6.3 |
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Less than High school | 60 | 4.6 | 58 | 3.9 | 22 | 1.4 | 28 | 2.6 |
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High school graduate | 292 | 14.1 | 235 | 11.5 | 105 | 5.9 | 93 | 5.7 |
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Some college | 509 | 24.1 | 491 | 21.0 | 334 | 17.8 | 282 | 14.0 |
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Bachelor’s | 359 | 10.1 | 378 | 11.7 | 303 | 9.9 | 346 | 14.0 |
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Post bacc. | 242 | 6.8 | 295 | 9.2 | 197 | 5.4 | 198 | 7.5 |
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Married | 848 | 35.1 | 794 | 33.9 | 564 | 24.8 | 495 | 22.5 |
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Single | 511 | 24.2 | 518 | 23.9 | 313 | 16.0 | 351 | 19.7 |
aMarital status was collapsed for simplicity into two categories: married (married or living as married) and single (single, divorced, separated, widowed).
Demographic and health behavior correlates of using the Internet for help with DWPA in 2007 and 2011.
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Did not use Internet for DWPA | Used Internet for DWPA | ||||||
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2007 | 2011 | 2007 | 2011 | ||||
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Mean | SD | Mean | SD | Mean | SD | Mean | SD |
Age |
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50.30 | 16.12 | 52.74 | 15.32 | 44.64 | 13.44 | 45.72 | 13.99 |
BMI |
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27.32 | 6.27 | 27.40 | 6.28 | 28.14 | 6.60 | 28.51 | 6.74 |
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Fruit intake | 2.42 | 1.38 | 2.38 | 1.36 | 2.72 | 1.36 | 2.54 | 1.36 |
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Vegetable intake | 2.77 | 1.31 | 2.67 | 1.36 | 3.03 | 1.33 | 2.88 | 1.32 |
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Moderate exercise | 3.35 | 1.84 | 2.68 | 2.21 | 3.57 | 1.75 | 2.81 | 2.06 |
aFruit (N=4816) and vegetable (N=4813) intake reflect cups per day; moderate exercise (N=4062) reflects days per week.
To determine whether more people used the Internet for DWPA in 2011 than in 2007, we conducted a multiple logistic regression including all of the demographic variables (age, gender, BMI, education, race, and marital status) and survey year. There was a trend that Internet users in 2011 were more likely to have used the Internet for DWPA than were Internet users in 2007 (OR 1.05, 95% CI 0.99-1.12,
To assess whether the makeup of users had changed between 2007 and 2011, we ran separate multiple logistic regressions in which the demographic variables, survey year, and an interaction term between the survey year and the demographic variable of interest were entered. There was no change across years in BMI (OR 1.00, 95% CI 0.99-1.01,
In general, people who used the Internet for DWPA in 2011 reported 2.54 cups of fruit intake per day, 2.88 cups of vegetable intake per day, and 2.81 days of exercise per week (see
We tested the associations between health behaviors and use of the Internet for DWPA using 3 multiple linear regressions, each controlling for all demographic variables (BMI, age, gender, education, race, and marital status) as well as survey year. People who used the Internet for DWPA reported more vegetable intake (beta=.08, B=.22, 95% CI 0.18-0.27,
Post hoc analyses were conducted to evaluate whether the relationships between health behaviors and using the Internet for DWPA held for minority groups (ie, non-Hispanic blacks and Hispanics). For the most part, the same positive pattern between health behaviors and use of the Internet for DWPA was observed among Hispanics and non-Hispanic blacks. However, among Hispanics, use of the Internet for DWPA was associated with lower exercise (beta=-.05, B=-.20, 95% CI -0.35 to -0.04,
To test whether the relationships between using the Internet for DWPA and health behaviors changed from 2007 to 2011, we created interaction terms between use of the Internet for DWPA and survey year, and added the interaction terms to the regressions described above. The interaction term was not associated with vegetable intake (beta=.001, B=.004, 95% CI -0.08 to 0.09,
The current study was the first to examine use of Internet-based DWPA programs in a nationally representative sample of the United States. In general, US adults who were younger, more educated, married, with higher BMIs, and nonwhite were more likely to use the Internet to help with DWPA. The findings for education and BMI are in line with findings from RCTs and studies on commercially available or open-access programs [
A trend indicated that a greater proportion of Internet users used the Internet for DWPA in 2011 than in 2007. This finding provides support for the increasing viability of the Internet as a platform that can reach large numbers of geographically dispersed people. As more people turn to the Internet for help with DWPA, developing and evaluating quality, evidenced-based online programs is of utmost importance.
Importantly, even when controlling for gender, BMI, age, and level of education, people who use the Internet to help with DWPA report greater fruit and vegetable intake and more physical activity than those who do not use the Internet for DWPA. There are a number of possible explanations for this finding. First, it may reflect pre-existing differences in adherence between those who turn to the Internet for DWPA information compared to those who do not. That is, those who use the Internet for DWPA may have greater interest, intent, or motivation towards DWPA than those who do not seek such information. Second, using the Internet for DWPA may help a person better manage healthy behaviors. However, due the correlational nature of the data, we cannot draw conclusions about the nature of the relationship. To address these causal questions, future studies should examine the relationship between using the Internet for DWPA and related health outcomes in a longitudinal, controlled trial.
We also found that despite more people using the Internet for DWPA in 2011 than in 2007, use in 2011 was associated with lower adherence to healthy DWPA behaviors than in 2007. One potential reason for this finding could be the higher availability of online programs and websites for DWPA; in 2007, it may have taken higher levels of motivation or intention to seek out a website or program for DWPA, and this higher level of motivation may also correspond to better health behaviors. With the proliferation of Internet sites providing DWPA-related information, future users of such sites may be expected to have lower levels of health-behavior adherence than observed in the past. Of course, another possibility is that DWPA-related Internet sites are becoming less effective in their provision of information such that their use leads to lower adherence, but the correlational nature of our data cannot address this possibility. As previously mentioned, only longitudinal, controlled trials can assess the effectiveness of current DWPA Internet sites in improving DWPA behavior.
The US Department of Agriculture and Department of Health and Human Services recommend that adults consume at least 2 cups of fruit and 2.5 cups of vegetables per day given a standard 2000-calorie diet and 150 minutes of moderate physical activity per week [
Although this study was the first to assess user characteristics and associated behaviors of using the Internet for DWPA with a nationally representative sample, it is not without limitations. One limitation was the dichotomous nature of our measure for using the Internet for DWPA; there was no way to ascertain an individual’s level of use (eg, yearly, weekly, daily), nor to tell the type or quality of the website or program they used. Second, because the 2007 and 2011 HINTS datasets used different samples, we could not make any longitudinal inferences from the data. Last, all data are self-reported, so our data on DWPA-related behaviors cannot be validated against objective measures.
The current study advances prior research by examining the demographic and health behavior correlates of Internet use for DWPA among a nationally representative US sample. As Internet use grows to near ubiquity in developed countries, our findings highlight the importance of evaluating Web-based programs, which may prove effective in health behavior change. The Internet represents a viable platform for targeting health behavior change across a large and growing audience, and future research should continue to explore this important topic.
diet, weight, and physical activity
Health Information National Trends Survey
randomized controlled trial
None declared.