Maintaining a Healthy Diet for Weight Loss

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Weight loss has many health benefits, but patients must be sure to maintain good nutrition throughout the process.

Currently, about 72% of men and 64% of women in the United States are overweight and approximately onethird are obese.^1,2 Over the past 30 years, obesity rates doubled, and they continue to rise. Research shows obesity as a major reversible risk factor for hypertension, diabetes mellitus, stroke, heart disease, and certain cancers.¹

Clinical Commentary

What role do pharmacists play in helping patients lose weight?

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Consequently, obesity has gained national media attention as a major health risk. Healthy People 2020, the national health promotion and disease prevention initiative from the US Department of Health and Human Services, has the goal of reducing obesity rates by 10%.³ The pharmacist, as one of the most accessible health care professionals, can take part in this national challenge by serving as a resource for patients wishing to lose weight.

Unfortunately, the Internet contains an excess of information regarding fad diets and rapid weight loss programs lacking validation or nutritional value. Misinformed patients may attempt to lose weight at the expense of adequate nutrition and put themselves at greater risk for other health conditions. Studies demonstrate that very-low-calorie diets (VLCDs) increase patients’ risk for gallstones and that weight loss leads to decreases in bone mineral density.^4,5 Pharmacists should be prepared to answer patient questions about maintaining adequate nutrition during weight loss and setting healthy weight loss goals.

A healthy diet, according to the 2010 American Dietary Association guidelines, emphasizes a caloric balance, in which the number of calories consumed is equally expended from physical activity and normal body functions. Daily caloric intake is person-specific; it depends on age, gender, height, weight, and physical activity. The major cause of obesity is an imbalance in caloric intake and energy expenditure. Patients who are consuming high-calorie foods that are also low in nutrients are not increasing physical activity to match their caloric intake.²

Losing Weight

According to the National Heart and Lung Institute (NHLI), weight loss goals are 3-fold: to reduce body weight, maintain body weight over the long term, and prevent further weight gain. Moreover, a combination of modalities, which includes diet therapy, physical activity, and behavioral therapy, is preferred and more effective than 1 modality alone. When counseling patients about weight loss, therefore, pharmacists must emphasize the importance of adjusting diet, increasing physical activity, and setting appropriate goals.⁴ The appropriate weight loss rate is a 10% loss of body weight over a 6-month period, which averages to be a loss of 1 to 2 lb per week. After 6 months, the decline will plateau because of changes in resting metabolic rate; basal energy expenditure typically decreases as weight decreases. At this point, readjustments may be necessary, such as further reducing caloric intake and/or increasing physical activity. Essentially, weight loss is achieved by a combination of 2 actions: decreasing caloric intake and increasing physical activity.⁴

Diet Therapy

The average caloric intake of US adults ranges between 1785 and 2640 calories per day, but due to underreporting, it may be higher.² Diet therapy uses the caloric balance to patients’ favor; by reducing daily caloric intake, the resulting negative caloric balance leads to weight loss. To achieve the appropriate weight loss rate, an initial decrease of 300 to 500 calories per day is recommended for patients with a body mass index (BMI) between 27 and 35 kg/m2, and a decrease of 500 to 1000 calories/day is suggested for patients with a BMI greater than 35 kg/m².

Notably, low-calorie diets (LCDs) consisting of 800 to 1500 calories per day are preferred to VLCDs, which consist of less than 800 calories per day. The NHLI presents the “Low Calorie Step I” diet, which also aims to decrease risk factors of hypertension and dyslipidemia (Table 1). Other LCDs are available through commercially advertised programs and vary by macronutrient composition, specifically carbohydrates. Studies investigating the impact of dietary macronutrient composition on weight loss failed to demonstrate a difference between diets.^4,6

Decreasing caloric intake to meet LCD goals should not come at the expense of adequate nutrition. To meet recommended daily values for vitamins and minerals, calories from nutrientdense foods are preferred. A brief overview of recommend

ed daily intake of major nutrients is provided in Table 2. Diets should consist of fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products. Patients can be instructed to also choose lean meats, poultry, fish, beans, eggs, and nuts for protein sources, and foods low in saturated fats, trans fats, cholesterol, sodium, and added sugars.^2,4

VLCDs induce rapid weight loss initially, but sustain total weight loss similar to LCDs after 1 year. Moreover, VLCDs fail to provide adequate nutrition, and they require proper supplementation and monitoring by a qualified health care professional. Therefore, pharmacists should counsel patients on only attempting a VLCD under the supervision of their primary care physician and/or nutritionist and only for a short period of time.^4,6

Physical Activity

Increasing physical activity is just as essential as restricting daily caloric intake and should be integrated into all weight loss programs. However, increased physical activity alone produces only about a 2% to 3% decrease in body weight; thus, it is best as an adjunct therapy rather than a sole means of achieving weight loss.

NHLI and the Physical Activity 2008 guidelines recommend that patients initially start moderate levels of physical activity for 30 to 45 minutes 3 to 5 days per week. A moderate increase in physical activity is generally recommended because it is associated with better patient adherence. To avoid injury in obese and overweight patients, increases in activity and intensity must be initiated slowly and gradually. Patients can progress from taking the stairs or walking more to regular moderate-intensity aerobic activity, such as cycling or swimming.^4,6,7

Pharmacotherapy and Dietary Supplements

A plethora of herbal and dietary supplements claiming to induce weight loss are sold in pharmacies and are regularly bought by patients. A recent systematic review of these alternative/herbal supplements reported that there is a lack of quality, safety, and efficacy in using these supplements for weight loss, and they should not be recommended. However, nutritional supplements such as multivitamins or combination calcium and vitamin D supplements could be recommended to patients who may not be able to meet nutrient requirements.⁸

The only FDA-approved medication to treat obesity is orlistat, which is available by prescription and over the counter (at a lower dose) as Xenical and Alli, respectively. Orlistat, a lipase inhibitor, has modest weight loss effects and can be used as an adjunct therapy. It is not effective, however, if used with a low-fat diet, and decreases absorption of fat-soluble vitamins. Pharmacists may want to recommend a multivitamin to patients taking this medication.⁹

Team Approach to Healthy Weight Loss

Clinical Commentary

Concerning weight loss, when should a pharmacist direct a patient to a physician?

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Participation of multiple health care professionals is essential for healthy weight loss. As one of the most accessible health care professionals, the pharmacist may be the first person patients approach when deciding to lose weight. Pharmacists can answer patients’ initial questions on weight loss goals, diet programs, and commonly sold herbal and alternative supplements. Counseling patients about OTC weight loss medication may also promote adherence. Moreover, patients should be referred to their primary care physician and/or nutritionist, so that an appropriate dietary and exercise plan is initiated and maintained. Take note that weight loss may be inappropriate for certain patients, such as most lactating or pregnant women and patients with uncontrolled psychiatric illness; for these patients, specialized care is required.⁴

Dr. Prescott is vice president, clinical and scientific affairs, for Pharmacy Times. Ms. Fedorenko is a PharmD candidate at the Ernest Mario School of Pharmacy at Rutgers University in Piscataway, New Jersey.

References

1. Centers for Disease Control and Prevention. U.S. Obesity Trends. www.cdc.gov/obesity/data/trends.html. Updated July 21, 2011. Accessed October 17, 2011.

2. US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2010. 7th ed Washington, DC: US Government Printing Office; December 2010.

3. US Department of Health and Human Services. Healthy people 2020: summary and objectives. http://healthypeople.gov/2020/topicsobjectives2020/objectiveslist.aspx?topicId=29. Updated September 29, 2011. Accessed October 17, 2011.

4. National Heart and Lung Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: Evidence Report. NIH publication No. 98-4083. September 1998. www.nhlbi.nih.gov/guidelines/obesity/ob_gdlns.pdf.

5. Shah K, Armamento-Villareal R, Parimi N, et al. Exercise training in obese adults prevents increase in bone turnover and attenuate decrease in hip BMD induced weight loss despite decline in bone-active hormones [published online ahead of print July 22, 2011]. J Bone Miner Res.doi:10.1002/jbmr.475.

6. Laddu D, Dow C, Hingle M, et al. A review of evidence-based strategies to treat obesity in adults. Nutr Clin Pract. 2011;26(5):512-525.

7. Department of Health and Human Services. 2008 Physical Activity Guidelines for Americans. ODPHP Publication No. U0036, October 2008.

8. Poddar K, Kolge S, Bezman L, et al. Neutraceutical supplements for weight loss: a systematic review. Nutr Clin Pract. 2011;26(5):539-552.

9. BrayGA, Ryan DH. Drug treatment of the overweight patient. Gastroenterology. 2007;132:2239-2252.