by Ashley Jordan Ferira, PhD, RDN

Diabetes has reached epidemic proportions in the US: 30 million US adults have diabetes (90-95% type 2 diabetes [T2D]), with another 84 million living with prediabetes.¹ The most influential, modifiable risk factors for diabetes include overweight/obesity, lack of physical activity, and smoking.¹ With diabetes-related medical costs and lost work/wages totaling $245 billion/year,¹ the US cannot afford to let this epidemic remain unchecked. Clinicians who are equipped to implement successful, evidence-based lifestyle interventions for their patients can be the game changers.

Characteristics of successful lifestyle weight loss interventions in overweight and obese adults with type 2 diabetes (T2D) include caloric energy restriction, a healthful dietary pattern, regular physical activity and frequent contact with health professionals.² Nutrition therapy (NT) plays a critical role in T2D management, and current standards of care recommend patients with T2D work with a registered dietitian nutritionist (RDN) to develop an individualized eating plan.³

“Effective management of HbA1C levels, while challenging, is critical to reducing the risk of diabetes-related complications,” according to Osama Hamdy, MD, PhD, FACE, Medical Director of the Obesity Clinical Program at Joslin Diabetes Center and Associate Professor at Harvard Medical School. Dr. Hamdy is the principal investigator of a randomized trial published in Nutrition Journal, which examined 3 lifestyle interventions head-to-head to determine the optimal NT model for improving HbA1c and cardiovascular disease (CVD) risk factors in overweight and obese patients with type 2 diabetes.⁴

The study included 108 patients (62 female, 46 male) 18 to 80 years of age with T2D and the following baseline characteristics (averages): age- 60; weight- 101.4 kg; BMI- 35.2; HbA1c- 8.07%.⁴ Participants were randomized into 1 of 3 NT lifestyle interventions, which they followed for 16 weeks. Participants maintained their baseline physical activity levels throughout the study. The 3 NT methods included:⁴

– Group A:  Met with RDN to develop individualized eating plan (utilized educational materials on the Plate Method and healthy eating)

– Group B:  Met with RDN and followed structured meal plan per Joslin Nutrition Guidelines for overweight and obese patients with T2D, including:

• Hypocaloric dietary plan: 1,500 kcal/day for women; 1,800 kcal/day for men
• 40-45% kcal from low-glycemic index carbohydrates, <10% saturated fat, 1-1.5 g protein/kg body weight, 14 g fiber per 1,000 kcal, sodium <2,300 mg/day
• Meal replacements: 1-3x/day using a diabetes-specific nutrition formula (DSNF), providing 220 kcal/serving, with a macronutrient calorie distribution of 40% carbohydrates/32.7% fat/27.3% protein and array of essential micronutrients
• Other tools (i.e. meal book, snack list, food log)

– Group C: Same features as Group B, in addition to increased patient-RDN interactions, including weekly phone coaching and support.

The following statistically significant results were demonstrated following 16 weeks of NT intervention:⁴

• All 3 groups experienced reductions in energy intake, total carbohydrates, total fat, and saturated fat
• HbA1c decreased in Groups B (-0.66%) and C (-0.61%), and non-significantly in Group A
• Body weight, % body fat and waist circumference decreased in Groups B and C, but not Group A
  • Average weight loss reduction: Group B lost 3.49 kg; Group C lost 2.93 kg
  • Average % body fat reduction: Group B lost 1.6%; Group C lost 1.2%
  • Average waist circumference reduction: Group B lost 5.0 cm; Group C lost 2.9 cm
• Visceral fat levels decreased significantly in Group B only

This rigorously-designed, head-to-head comparison of NT methods demonstrated that all three NT approaches improved diet quality and reduced energy intake. However, the structured dietary intervention (Groups B and C) was superior to an individualized eating plan (Group A) in helping patients improve glycemic control and CVD risk factors. The DSNF meal replacement was one of the important, differentiating features of the structured meal plan approach.

Why is this Clinically Relevant?

• Successful, sustainable lifestyle intervention approaches are needed to combat the diabetes epidemic
• Meal replacements play an important, strategic role in weight loss and long-term disease management⁵
• RDNs play an integral, front line role in partnering with patients with T2D to develop and implement individualized or structured NT interventions, and the latter is likely the superior approach⁴
• Per Dr. Hamdy, the lead author of the study:⁴ “These data are encouraging, as overweight adults with type 2 diabetes now have a more effective approach to reducing A1C and body weight through a structured dietary plan.”

Link to article

Citations

1. CDC. Diabetes quick facts. https://www.cdc.gov/diabetes/basics/quick-facts.html. Accessed April 23, 2018.
2. Franz MJ, Boucher JL, Rutten-Ramos S, VanWormer JJ. Lifestyle weight-loss intervention outcomes in overweight and obese adults with type 2 diabetes: a systematic review and meta-analysis of randomized clinical trials. J Acad Nutr Diet. 2015;115(9):1447-1463.
3. ADA. Lifestyle Management. Sec. 4. In: Standards of medical care in diabetes-2017. Diabetes Care. 201740:S33-43.
4. Mottalib A, Salsberg V, Mohd-Yusof BN, et al. Effects of nutrition therapy on HbA1c and cardiovascular disease risk factors in overweight and obese patients with type 2 diabetes. Nutr J. 2018;17:42.
5. Heymsfield SB, van Mierlo CA, van der Knaap HC, Heo M, Frier HI. Weight management using a meal replacement strategy: meta and pooling analysis from six studies. Int J Obes Relat Metab Disord. 2003;27(5):537-549.