Lifestyle Change as a Cost-Effective Alternative to Medication

Executive Summary

Chronic conditions are the most expensive and prevalent health concern today, with consequences including complications and comorbidities, and costs due to medical expenses and lost productivity. Prescription medications can often help manage chronic diseases, but their drawbacks can include high upfront costs, side effects or complications, and lack of effectiveness due to low adherence. Lifestyle changes are known to lower risk for and help control many chronic conditions, including hypertension, heart disease, depression, certain cancers, and diabetes. Healthy changes include losing excess weight, increasing physical activity, following a more prudent diet, getting adequate sleep, and managing stress. The Diabetes Prevention Program (DPP) is an example of a lifestyle intervention that is proven to be effective and cost-effective. Lark DPP is a digital DPP powered by AI that can increase engagement, improve outcomes, facilitate implementation, and lower costs. Ultimately, lifestyle changes can offer an approach to chronic disease prevention and management that can cost less than medicine.

Chronic Conditions: Dominant but Preventable and Treatable

Chronic and mental health conditions are the dominant health issue in the U.S., accounting for 90% of healthcare costs [1] and well over $1 billion annually in lost productivity. [2] The health costs are also staggering, with chronic diseases accounting for six of the top seven causes of U.S. deaths along with disabilities and complications.

Diabetes, in particular, accounts for 1 in 4 healthcare dollars spent and has an annual nationwide cost of $327 billion in medical care and lost productivity. [3] Over 30 million Americans have diabetes, with type 2 diabetes accounting for 90 to 95%, and are at risk for heart disease, stroke, and complications such as blindness, kidney disease, and peripheral neuropathy. Another 86 million Americans, or 1 in 3 adults, have prediabetes and are at high risk for developing diabetes. Without proper treatment, 37% of those diagnosed with prediabetes develop diabetes within four years. [4]

Like other chronic diseases, type 2 diabetes is largely attributable to obesity and other modifiable risk factors related to lifestyle choices. It is often preventable among adults with insulin resistance that is minimal or has already led to prediabetes. Healthy behavior changes can reverse insulin resistance, stop the progression of prediabetes, or delay the onset of diabetes. [5] They can also ultimately cost less than medications because of their low-cost nature, their high efficacy, and their safety which can tip the scales in the drugs versus lifestyle change debate.

Lifestyle Changes Work

Recognition that the impacts of chronic diseases are not inevitable is becoming more widespread. Healthier lifestyles can prevent 40% of cancer cases and 80% of heart disease, stroke, and diabetes cases, according to the World Health Organization (WHO). [6] Lifestyle changes that can contribute to improvements in insulin resistance and blood sugar include weight loss, increased physical activity, healthier food choices, and additional supportive choices.

Weight Loss

Overweight and obesity are major risk factors for diabetes and other chronic diseases. One study found that 85% of people with type 2 diabetes were overweight or obese. [7] Those with a body mass index (BMI) over 35 kg/m2 have 42 times the risk of developing diabetes compared to those with a normal-weight BMI. Weight loss is as effective as excessive weight is risky. Losing a kilogram of body weight lowers diabetes risk by 16%, while losing 7 percent of body weight can lower diabetes risk by over half.

Nutrition

Independent of weight loss, healthier eating can prevent chronic diseases. An eating plan similar to the Dietary Approaches to Stop Hypertension (DASH) diet, for example, can lower high systolic blood pressure by 11 mmHg. Lowering sodium consumption can lower systolic blood pressure by mmHg, while increasing potassium consumption can lower systolic blood pressure by mmHg. [8]

Similarly, certain dietary patterns and healthy improvements have been shown to lower blood sugar and risk for diabetes. Diet patterns higher in cereal fiber and lower in trans fat, for example, are associated with lower risk for diabetes. [9] So is a “prudent diet,” with higher consumption of olive oil, fruit, vegetables, legumes, whole grains, and nuts, and lower consumption of meat, sweets, and refined grains. [10] The evidence is considered strong for a protective effect of whole grains and a deleterious effect of processed meats and sugar-sweetened beverages, and moderate for a protective effect of fish, vegetables, fruit, and dairy. [11] Certain foods and nutrients have medicinal properties because they do affect insulin resistance. Reducing alcohol intake has a large effect as well.

For diet plan for prediabetes, see our guide here.

Physical Activity

Physical activity is another lifestyle component that can act like medication without the economic costs or side effects. Higher physical fitness levels are associated with lower risk of hypertension, chronic obstructive pulmonary disease (COPD), diabetes, and total cholesterol, and changes in physical fitness affect the risk of disease accordingly. Physical activity is effective in the primary and secondary prevention of cardiovascular disease, osteoporosis, and diabetes. [12] It improves insulin resistance and glycemic control, and the ADA recommends aerobic activity and strengthening exercises for preventing and managing diabetes. [13]

Looking for a way to start working out as a diabetic? We’ve laid out the 8 Best Exercises for Managing Your Diabetes Easier.

And More

Other lifestyle factors can improve health. Chronic stress and life stressors can suppress the immune system and trigger inflammatory responses, and are risk factors for chronic conditions including hypertension, hypercholesterolemia, coronary heart disease, and type 2 diabetes. [14] Stress management, including “relaxation and meditative techniques,” [15] can help.

Sleep is another lifestyle factor that can be as effective as medication. Sleep deprivation has physiological effects, including changes in hormone balance and glucose metabolism, and increases hunger and cravings. Being short on sleep is linked to hypertension, diabetes, and cardiovascular diseases. [16]

The Lure and Disappointment of Medication

Medications should be considered when lifestyle changes do not work, but they are too often the first-line treatment. Patients might want prescriptions because taking pills seems easier than making behavior changes (mos
t people find it easier to take a pill than to pass up dessert) and they may perceive that medications are more effective. Doctors can be tempted to prescribe them to satisfy patients’ demands or, sadly, because they do not know any better.

While medicine can be life-changing and life-saving, it has drawbacks. First, it only works as intended when patients take it as intended, and that does not happen too often. The average is about 50% compliance, with poorer adherence in certain cases such as when medications are more expensive or have more severe side effects, as in the case of gastrointestinal discomfort when taking metformin. [17] Reasons for poor compliance include high costs, forgetting to fill prescriptions or take doses, not understanding the importance of the medication, and not feeling sick or wanting to act sick.

Medications post another problem: cost. They can seem cheap from a narrow perspective. It can indeed be less expensive to go on one of the standard, relatively inexpensive medications, such as statins, for a few months than to provide a patient with a live support system and any other support needed to lose weight or make other recommended lifestyle changes.

However, this calculation assumes only one or a few inexpensive medications and considers only a short period of time with no side effects or complications from the drug. The calculations yield different results when considering the actual cost of drugs, which averages nearly $1,400 per person per year. [18] While some drugs, such as many cholesterol-lowering statins, cost only cents a day, others, such as many types of insulin, cost dollars each day. This is ironic given that when insulin is prescribed in type 2 diabetes, it is being used to manage a condition that almost certainly could have been prevented with diet and exercise.

The DPP is an example of a lifestyle change program whose costs and benefits have been extensively analyzed and compared to the effects of the prescription drug and the blood sugar-lowering medication metformin. The initial and follow-up studies have shown that weight loss and exercise can be more effective than metformin at lowering diabetes incidence.

Cost analyses further cast favorable light on lifestyle changes. Using standard estimates based on middle-of-the-road projections for participation and outcomes, payors are generally expected to see up to a 42% ROI within 3 years of beginning to cover a DPP for their covered participants. [19] As if direct cost savings from health gains were not enough, the cost per quality-adjusted life-year (QALY) was approximately $1,100 for the lifestyle intervention, versus $31,300 for the metformin intervention. [20]

Promise and Challenge of Lifestyle Medicine

Think about the old adage, “An apple a day keeps the doctor away.” Then amplify it to see food as medicine. Add other aspects of lifestyle, such as physical activity, stress management, and sleep, and the result is a powerful bag of tools that could be as effective as medications in preventing and/or treating the most expensive and prevalent chronic conditions.

The potential of lifestyle interventions is becoming so well recognized that such treatment is an emerging field of medicine known as lifestyle medicine (LM). The approach is not an unproven art based on rumors and beliefs, but rather an evidence-based discipline that applies the multiple risk factor model to “prevent, treat and reverse the progression of chronic diseases” with “comprehensive lifestyle changes (including nutrition, physical activity, stress management, social support and environmental exposures).” [21]

The produce prescription program is an example of using LM in place of prescription drugs. [22] In the program, doctors write prescriptions for patients and their families who are at risk for food insecurity and diet-related diseases: think obesity, diabetes, hypertension, and heart disease, for starters. The “catch” is that the prescription is not for drugs from a pharmacy, but for reimbursement for purchases of fruit and vegetables from farmers’ markets.

The cost is $1 per day for the patient and each other member of the patient’s household. With 47% of participants lowering their BMI and reducing other health risks, the program has demonstrated success at a cost lower than many medications, and with no side effects.

Desire and Shortcomings in the Medical Field

Doctors, hospitals, and payors who truly want to help their patients can embrace LM. It offers them another avenue for keeping patients healthy or reducing the progression and impacts of their conditions. Without fearing side effects or complications, doctors can prescribe produce and recommend other healthy lifestyle behaviors to patients who are healthy, are at risk for chronic conditions, or are managing conditions.

It is simple in theory, but more challenging in practice. One barrier is the lack of preparation for physicians to counsel patients on diet, exercise, and other healthy choices. Even if they are aware of the benefits of healthy lifestyles – which they may not be – they are unlikely to know how to coach their patients on them. They may not know how to motivate them to lose weight or get active, or how to create a meal or exercise plan, especially a customized plan for an individual who may have certain limitations or specifications because of a disease state or specific health goal. Doctors simply may not feel comfortable addressing obesity. [23]

Doctors’ discomfort with or inability to address lifestyle factors may first be unbelievable given that their job is to keep you healthy, but the situation makes more sense when considering their training. Medical school falls woefully short in areas related to health behaviors. Take nutrition as an example. The National Academy of Sciences requires 25 hours of nutrition education. That already paltry amount – about 2% of the hours required in a dietetic internship – is met only by 38% of medical schools. [24]

There is another barrier to providing lifestyle counseling: who has time? Most doctors do not. There is a known shortage of physicians which is expected to grow over the next several years. [25] Doctors have limited time in their appointments with patients. [26] During the span of a 15-minute appointment that also covers the exam and the patients’ questions and health concerns, a doctor is unlikely to be able to outline a realistic meal plan and exercise program, much less work out a shopping list and recipes. With the time pressure, it may be easier or seem more sensible to write a prescription for medications, possibly with some vague advice to “eat well” or “get some exercise.”

Diabetes Prevention Program as an Example of Prevention through Lifestyle

There is an already-established lifestyle change program that has been proven effective in preventing a major chronic disease, and that doctors can refer patients to. The national Diabetes Prevention Program (DPP) is an evidence-based lifestyle change program that emphasizes go
als of losing 7% of body weight and achieving at least 150 minutes per week of moderate-intensity physical activity. A landmark study compared the effects of this lifestyle change program to those of using metformin among patients with prediabetes. Researchers found that participants assigned to the lifestyle intervention had a 58% lower chance of developing diabetes, while participants using metformin had a 31% lower risk, compared to participants in the placebo (control) group. [27]

With these outcomes, researchers calculated that 1 case of type 2 diabetes would be expected to be prevented for each 6.9 participants in a DPP, while 1 case of diabetes would be prevented for each 13.9 patients treated with metformin. Further analysis showed a delay of the onset diabetes of 11 years with lifestyle intervention and 3 years with metformin. [28]

Cost Savings through Prevention with Lifestyle

Experts tend to agree that disease prevention with prudent programs can be more cost-effective than treating diseases after they advance. Non-pharmaceutical approaches based on evidence include education (such as ad campaigns and email newsletters), screening (such as at health fairs and in doctors’ offices), and changing the environment (such as having fruit in vending machines and paying for employees’ gym memberships) to make healthy behaviors easier. The American Public Health Association (APHA) provides some estimates on the ROI of each $1 put into prevention. [29]

• $5.60 in health spending within five years for “evidence-based programs that increase physical activity, improve nutrition and prevent tobacco use.”
• $3.27 in reduced medical costs and $2.37 in reduced absenteeism with workplace wellness programs.
• $1.26 saved through tobacco cessation programs.

More specifically, the delay and prevention of type 2 diabetes with a DPP can translate into cost savings. Each case of diabetes that is prevented saves an average of $2671 per year. [30] This value shows not only that diabetes prevention is valuable, but also that delay of diabetes onset is valuable. Each delay in the onset of diabetes delays the more expensive treatments, such as trips to the emergency room or diabetes medications at a cost of up to thousands of dollars per year. It also delays the development of diabetes complications and their associated costs.

Further Cost Observations of Lifestyle versus Medicine

Lifestyle interventions are becoming increasingly accepted as effective for health promotion compared to medicines. Because they prevent or delay diseases and complications, they can save money on medical treatments and lost productivity. The other side of a cost-savings analysis is the cost of the treatment. Lifestyle treatments can be relatively inexpensive when compared to medications.

The DPP provides excellent data for economic comparisons between lifestyle and medication treatment for improving health among prediabetes patients through diabetes prevention. Standard calculations estimate the 3-year ROI for a national DPP to be up to 42%. [31]

An Artificial Intelligence Diabetes Prevention Program as a Ready Solution

Despite its proven effectiveness and reasonable costs, the DPP is used only by 1 to 11% of those patients who might be eligible. [32] Patients, healthcare professionals, and payors may all experience barriers to greater participation. [33] Reasons for not participating in a DPP may include cost of the program, lack of knowledge about or awareness of it, distrust of the program or its curriculum, lack of expertise in the subject matter, and trouble committing to the year-long program.

Diabetes Prevention Program in Practice

Running a DPP is a significant undertaking. For their programs to receive full recognition from the Centers for Disease Control and Prevention (CDC), DPP providers must meet criteria such as having trained DPP lifestyle coaches, using a CDC-provided or approved curriculum, providing the CDC with regular reports, and achieving benchmarks related to weight loss outcomes and participation. [34] Choosing the right DPP provider can help payors avoid these logistical problems. Lark Health has achieved Full CDC Recognition as of 2019.

Digital Diabetes Prevention Program

A digital DPP could provide further benefits. For the participant, the program is more convenient when accessible through the phone, on demand, at any time and anywhere. There is no need to attend sessions on site at predetermined times, nor is there any need to make appointments ahead of time. The patient can be confident with weigh-ins and discussions of physical activity without a fear of shyness or stigma because of the presence of other patients or the lifestyle coach. Patients can also access their digital coaches anytime rather than only at designated times, possibly once per week or once a month.

For payors, a digital DPP can be lower in cost. Since lessons are given over the smartphone and not in person, there is no cost, such as rent of the space, associated with hosting the lessons. The program can be infinitely and immediately scalable without extra costs, since additional lifestyle coaches and other personnel need not be hired.

These costs savings do not come at the cost of quality. Digital programs have been found to be comparable to in-person ones. Lark DPP, a fully digital program, found that the average weight loss of users was comparable to that of patients in weight loss programs with in-person components. [35]

The Power of Artificial Intelligence

Artificial intelligence (AI) adds more advantages to a digital program. It allows creators to develop a program that is customized for each user, with the degree of customization increasing as users continue to use it and the AI “learns” about the user.

The final product delivered by the AI appears to the DPP patient as a single coach, but it is really the result of the input of a range of experts. While a single doctor may have a few hours of training in diet and physical activity, and a DPP lifestyle coach may be narrowly trained to teach the DPP curriculum, the AI can reflect the expertise of multiple specialists. Lark DPP, for example, is backed by a panel of professionals with education and experience in nutrition, physical activity, sleep, and lifestyle behaviors, including with a focus in glucose metabolism, insulin resistance, and diabetes prevention.

Lark Diabetes Prevention Program

Lark DPP helps the DPP realize its full potential for reach and outcomes at a reasonable cost. Lark DPP includes an evidence-based coaching program that incorporates elements of widely-accepted theories of behavior change. It is built using the expertise of specialists in lifestyle behaviors, obesity management, and diabetes prevention and management.

The program is fully digital, allowing it to maximize patient accessibility and convenience, while keeping unnecessary costs down. The AI coach presents not only the CDC Prevent T2 DPP curriculum, but also more in-depth coaching on the DPP’s core areas of losing weight and increasing physical activity, as well as guidance on nutrition and other lifestyle choices, such as getting adequate sleep and managing stress.

The fully digital nature of the program permits payors to offer it to all their covered population regardless of location. Payors can confidently offer the program knowing that Lark takes charge of logistics such as reporting to the CDC and sending out digital scales to patients, and that charges are results-dependent. Lark Health, Fully CDC Recognized, and our DPP is clinically validated. Another reason for peace of mind is the ability to scale the program instantly and infinitely while maintaining the ability for each patient to experience a customized program.

The savvy payor needs to keep its population as healthy as possible for as little cost as possible. Medications are frequently helpful and necessary, but in many situations, lifestyle change can be less costly and as effective. This is often true in the case of management and prevention of chronic diseases, which are the most expensive and prevalent health concerns in the country today. The DPP offers a realistic, low-cost approach to preventing diabetes and saving on healthcare costs and the costs of lost productivity.

References

1. National Center for Chronic Disease Prevention and Health Promotion. Health and Economic Costs of Chronic Diseases. https://www.cdc.gov/chronicdisease/about/costs/index.htm. Reviewed February 2, 2017. Accessed March 8, 2019
2. Graf M, Waters H. The cost of chronic diseases in the U.S. Milken Institute. May 2018. https://assets1b.milkeninstitute.org/assets/Publication/Viewpoint/PDF/Chronic-Disease-Executive-Summary-r2.pdf
3. American Diabetes Association. Economic Costs of Diabetes in the U.S. in 2017. Diabetes Care 2018;41(5):917-928.
4. Tuso P. Prediabetes and lifestyle modification: time to prevent a preventable disease. Perm J. 2014;18(3):88-93. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4116271/
5. Dunkley AJ, Bodicoat DH, Greaves CJ, Russell C, Yates T, Davies MJ, et al. Diabetes prevention in the real world: effectiveness of pragmatic lifestyle interventions for the prevention of type 2 diabetes and of the impact of adherence to guideline recommendations: a systematic review and meta-analysis. Diabetes Care 2014 Apr;37(4):922-933.
6. World Health Organization. Chronic diseases and health promotion: Preventing chronic diseases: a vital investment. https://www.who.int/chp/chronic_disease_report/part1/en/index11.html
7. Wild SH, Byrne CD. ABC of obesity. Risk factors for diabetes and coronary heart disease. BMJ. 2006;333(7576):1009-11.
8. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol 2018;71:e127-e248 https://www.jacc.org/doi/10.1016/j.jacc.2017.11.006?_ga=2.204312528.1948270614.1550184802-608566656.1548798866
9. Frank B. Hu, M.D., JoAnn E. Manson, M.D., Meir J. Stampfer, M.D., Graham Colditz, M.D., Simin Liu, M.D., Caren G. Solomon, M.D., and Walter C. Willett, M.D. Diet, Lifestyle, and the Risk of Type 2 Diabetes Mellitus in Women. N Engl J Med 2001; 345:790-797. DOI: 10.1056/NEJMoa010492. https://www.nejm.org/doi/full/10.1056/NEJMoa010492
10. Salas-Salvadó J, Martinez-González MÁ, Bulló M, Ros E. The role of diet in the prevention of type 2 diabetes. Nutr Metab Cardiovasc Dis. 2011 Sep;21 Suppl 2:B32-48. doi: 10.1016/j.numecd.2011.03.009. Epub 2011 Jul 13.
11. Schwingshackl L, Hoffmann G, Lampousi AM, et al. Food groups and risk of type 2 diabetes mellitus: a systematic review and meta-analysis of prospective studies. Eur J Epidemiol. 2017;32(5):363-375.
12. Warburton DE, Nicol CW, Bredin SS. Health benefits of physical activity: the evidence. CMAJ. 2006;174(6):801-9.
13. American Diabetes Association. Standards of medical care in diabetes – 2019. Diabetes Care 2019 Jan; 42(Supplement 1): S1-S2. https://doi.org/10.2337/dc19-Sint01. https://care.diabetesjournals.org/content/diacare/suppl/2018/12/17/42.Supplement_1.DC1/DC_42_S1_Combined_FINAL.pdf
14. Salleh MR. Life event, stress and illness. Malays J Med Sci. 2008;15(4):9-18.
15. Sarris J, O’Neil A, Coulson CE, Schweitzer I, Berk M. Lifestyle medicine for depression. BMC Psychiatry. 201414:107. https://doi.org/10.1186/1471-244X-14-107
16. von Ruesten A, Weikert C, Fietze I, Boeing H. Association of Sleep Duration with Chronic Diseases in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study. PLOS One. January 25, 2012https://doi.org/10.1371/journal.pone.0030972
17. Brown MT, Bussell JK. Medication adherence: WHO cares?. Mayo Clin Proc. 2011;86(4):304-14.
18. Williams S. The average American spends this much on prescription drugs each year. The Motley Fool. https://www.fool.com/investing/general/2015/12/12/the-average-american-spends-this-much-on-prescript.aspx. December 12, 2015. Accessed March 12, 2019.
19. American Medical Association. DPP cost saving calculator. https://ama-roi-calculator.appspot.com/
20. Herman WH, Hoerger TJ, Brandle M, et al. The cost-effectiveness of lifestyle modification or metformin in preventing type 2 diabetes in adults with impaired glucose tolerance. Ann Intern Med. 2005;142(5):323-32.
21. Egger G, Binns A, Rossner S. Lifestyle Medicine, 2nd edn. Sydney, Australia: McGraw‐Hill, 2011.
22. Wholesome Wave. https://www.wholesomewave.org/ Accessed March 11, 2019
23. Adams KM, Kohlmeier M, Zeisel SH. Nutrition education in U.S. medical schools: Latest update of a national survey. Academic Medicine: September 2010 - Volume 85 - Issue 9 - p 1537-1542. doi: 10.1097/ACM.0b013e3181eab71b
24. Adams KM, Kohlmeier M, Zeisel SH. Nutrition education in U.S. medical schools: Latest update of a national survey. Academic Medicine: September 2010 - Volume 85 - Issue 9 - p 1537-1542. doi: 10.1097/ACM.0b013e3181eab71b
25. IHS Markit Ltd. The Complexities of Physician Supply and Demand: Projections from 2016 to 2030. Association of American Medical Colleges. March 2018. https://aamc-black.global.ssl.fastly.net/production/media/filer_public/85/d7/85d7b689-f417-4ef0-97fb-ecc129836829/aamc_2018_workforce_projections_update_april_11_2018.pdf
26. Polak R, Pojednic RM, Phillips EM. Lifestyle Medicine Education. Am J Lifestyle Med. 2015;9(5):361-367. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4561845/
27. Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. February 7, 2002. N Engl J Med. 2002; 346:393-403. DOI: 10.1056/NEJMoa012512 https://www.nejm.org/doi/full/10.1056/NEJMoa012512
28. Herman WH, Hoerger TJ, Brandle M, et al. The cost-effectiveness of lifestyle modification or metformin in preventing type 2 diabetes in adults with impaired glucose tolerance. Ann Intern Med. 2005;142(5):323-32.
29. American Public Health Association. Public health and chronic disease: Cost savings and return on investment. https://www.apha.org/~/media/files/pdf/factsheets/chronicdiseasefact_final.ashx
30. Khan T, Tsipas S, Wozniak G. Medical Care Expenditures for Individuals with Prediabetes: The Potential Cost Savings in Reducing the Risk of Developing Diabetes. Popul Health Manag. 2017;20(5):389-396. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5649409/
31. Khan T, Tsipas S, Wozniak G. Medical Care Expenditures for Individuals with Prediabetes: The Potential Cost Savings in Reducing the Risk of Developing Diabetes. Popul Health Manag. 2017;20(5):389-396. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5649409/
32. Venkataramani, Maya et al. Prevalence and Correlates of Diabetes Prevention Program Referral and Participation. American Journal of Preventive Medicine, Volume 0, Issue 0. https://www.ajpmonline.org/article/S0749-3797(18)32334-1/fulltext
33. Johnson, DrPH, MPH, MA, L., & Stephanie T. Melton, PhD, MPH, MA. "Perceived Benefits and Barriers to the Diabetes Prevention Program." PLAID: People Living with And Inspired by Diabetes [Online], 2.1 (2016): n. pag. Web. 13 Mar. 2019.
34. Centers for Disease Control and Prevention. Diabetes Prevention Recognition Program: Standards and Operating Procedures. March 1, 2018. OMB No. 0920-0909. https://www.cdc.gov/diabetes/prevention/pdf/dprp-standards.pdf
35. Stein N, Brooks K. A Fully Automated Conversational Artificial Intelligence for Weight Loss: Longitudinal Observational Study Among Overweight and Obese Adults. JMIR Diabetes 2017;2(2):e28. DOI: 10.2196/diabetes.8590