|Risk Factor||Defining Level|
|*Overweight and obesity are associated with insulin resistance and the metabolic syndrome. However, the presence of abdominal obesity is more highly correlated with the metabolic risk factors than is an elevated BMI. Therefore, the simple measure of waist circumference is recommended to identify the body weight component of the metabolic syndrome.|
|†Some male patients can develop multiple metabolic risk factors when the waist circumference is only marginally increased, eg, 94 to 102 cm (37 to 39 in). Such patients may have a strong genetic contribution to insulin resistance. They should benefit from changes in life habits, similarly to men with categorical increases in waist circumference.|
|‡The American Diabetes Association has recently established a cutpoint of ≥100 mg/dL, above which persons have either prediabetes (impaired fasting glucose) or diabetes. This new cutpoint should be applicable for identifying the lower boundary to define an elevated glucose as one criterion for the metabolic syndrome.|
|Abdominal obesity, given as waist circumference*†|
|Men||>102 cm (>40 in)|
|Women||>88 cm (>35 in)|
|Blood pressure||≥130/≥85 mm Hg|
|Fasting glucose||≥110 mg/dL‡|
PDM: Scope of Guideline (2014)
Guideline Scope Characteristics
Below you will find a list of characteristics that describe the Scope of this Guideline.
The purpose of this guideline is to provide evidence-based recommendations for RDNs in providing medical nutrition therapy for individuals who are at high risk for type 2 diabetes.
While there are several risk factors for the development of type 2 diabetes, individuals who are at high risk for type 2 diabetes include, but are not limited to, the following:
Individuals with prediabetes, based on the definition from the American Diabetes Association:
Identified by one of the following:
- Impaired fasting glucose (IFG): fasting level of 100-125 mg/dL
- Impaired glucose tolerance (IGT): 2-h plasma glucose of 140-199 mg/dL (7.8-11.0 mmol/L)
- A1C: 5.7% to 6.4%
Adults with metabolic syndrome, based on the following two definitions from the ATP III and WHO:
WHO Clinical Criteria for Metabolic Syndrome
Insulin resistance, identified by one of the following:
- Type 2 diabetes
- Impaired fasting glucose
- Impaired glucose tolerance or for those with normal fasting glucose levels (>110 mg/dL), glucose uptake below the lowest quartile for background population under investigation under hyperinsulinemic, euglycemic conditions
Plus any two of the following risk factors:
- Antihypertensive medication and/or high blood pressure (≥140 mm Hg systolic or ≥90 mm Hg diastolic)
- Plasma triglycerides ≥150 mg/dL (≥1.7 mmol/L)
- HDL cholesterol <35 mg/dL (<0.9 mmol/L) in men or <39 mg/dL (<1.0 mmol/L) in women
- BMI ≥30 kg/m2 and/or waist:hip ratio >0.9 in men, >0.85 in women
- Urinary albumin excretion rate >20 g/min or albumin:creatinine ratio ≥30 mg/g
Counseling, Diagnosis, Evaluation, Management, Prevention, Risk Assessment, Screening, Treatment
Cardiology, Dentistry, Endocrinology, Family Practice, Geriatrics, Internal Medicine, Nephrology, Nursing, Nutrition, Obstetrics and Gynecology, Ophthalmology, Pediatrics, Pharmacology, Physical Medicine and Rehabilitation, Podiatry, Preventive Medicine, Psychiatry, Psychology, Sleep Medicine, Sports Medicine, Surgery
Registered Dietitians, Advanced Practice Nurses, Allied Health Personnel, Clinical Laboratory Personnel, Dentists, Health Care Providers, Hospitals, Managed Care Organizations, Nurses, Nurse Midwives, Optometrists, Pharmacists, Physical Therapists, Physician Assistants, Physicians, Podiatrists, Psychologists/Non-physician Behavioral Health Clinicians, Public Health Departments, Social Workers
To provide evidence-based recommendations on medical nutrition therapy for individuals who are at high risk for type 2 diabetes.Specific Objectives
- To define evidence-based nutrition recommendations for RDNs that are carried out in collaboration with other healthcare providers
- To guide practice decisions that integrate medical, nutritional and behavioral strategies
- To reduce variations in practice among RDNs
- To provide the RDN with data to make recommendations to adjust MNT or recommend other therapies to achieve desired outcomes
- To develop guidelines for interventions that have measurable clinical outcomes
- To define the highest quality of care within cost constraints of the current healthcare environment.
Adolescent (13 to 18 years), Adult (19 to 44 years), Middle Age (45 to 64 years), Aged (65 to 79 years), Advanced Aged (80 years and over), Male, Female
Target Population Description
Individuals who are at high risk for type 2 diabetes, such as individuals with prediabetes and adults with metabolic syndrome.
Interventions and Practices Considered
This guideline is based on the Academy of Nutrition and Dietetics Nutrition Care Process and Model, which involves the following steps:
- Nutrition assessment
- Nutrition diagnosis
- Nutrition intervention
- Nutrition monitoring and evaluation.
Academy of Nutrition and Dietetics. Position of the Academy of Nutrition and Dietetics: The Role of Nutrition in Health Promotion and Chronic Disease Prevention. J Acad Nutr Diet 2013;113:972-979.
Alberti KG, Zimmet PZ. Definition, diagnosis and classification of diabetes mellitus and its complications. Part 1: diagnosis and classification of diabetes mellitus provisional report of a WHO consultation. Diabet Med 1998;15(7):539-553.
American Diabetes Association. Standards of medical care in diabetes - 2013. Diabetes Care 2013;36 Suppl 1:S11-S66.
Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults. Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). JAMA 2001;285:2486-97.
Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Pressure in Adults (Adult Treatment Panel III) final report. Circulation 2002;106(25):3143-3421.
Major Outcomes Considered
These recommendations focus on the following major outcomes:
- Glycemic outcomes (specifically fasting blood glucose, 2 hour post prandial blood glucose, and A1C)
- Lipid outcomes (specifically triglycerides and HDL cholesterol levels)
- Anthropometric outcomes (specifically waist circumference and waist-to-hip ratio)
- Blood pressure outcomes (specifically systolic and diastolic blood pressure)
- Renal outcomes (specifically urinary albumin excretion rate and albumin:creatinine ratio).
These outcomes are the diagnostic markers of prediabetes (as defined by the American Diabetes Association) and/or metabolic syndrome (as defined by ATP III or WHO). In addition, based on the Position of the Academy of Nutrition and Dietetics: The Role of Nutrition in Health Promotion and Chronic Disease Prevention, obesity and family history are the main predictors of type 2 diabetes, and hypertension, low HDL cholesterol levels and high triglyceride levels are also predictive of type 2 diabetes risk.
The focus of this analysis was to separate out the impact of each intervention, on specified outcomes, without the influence of weight loss. The evidence analysis, on the impact of specific interventions, was based on randomized controlled trials (class A), cohort trials (class B) and nonrandomized clinical studies (class C) that control for the impact of significant weight loss, meaning that one of the following existed in each study included:
In taking this approach, any studies resulting in weight loss (such as the landmark studies on prevention of type 2 diabetes) only appear in the evidence analysis for weight loss (and possibly medical nutrition therapy if the intervention was provided by a registered dietitian nutritionist). For the evidence analysis on weight loss, a Cochrane review published in 2008 which included the landmark studies on prevention of type 2 diabetes (such as the Diabetes Prevention Program, Finnish DPS, Indian DPP, Da Qing IGT and Diabetes Study, etc.) was included to represent these historical findings, and more recently published research was added to the evidence analysis.
- No statistically significant (P<0.05) weight loss occurred between or within groups during the course of the study
- Statistically significant weight loss occurred between or within groups, but it was controlled for in the statistical analysis
- Statistically significant weight loss was similar between and within groups, but the interventions studied were different
Medical nutrition therapy and weight loss are strongly recommended for individuals at high risk for type 2 diabetes, because it is effective. The recommendations are written for individuals who are at high risk for type 2 diabetes, including adolescents. Reduction of energy may not be appropriate for all individuals, therefore, the registered dietitian nutritionist is referred to the Adult Weight Management, Pediatric Weight Management and Vegetarian Nutrition projects for more specific evidence-based recommendations on individualizing the weight loss approach. Physical activity, independent of weight loss and dietary change, has a paucity of data and therefore cannot be graded strong. Further studies, on the impact of these intervention are needed to truly elucidate their independent impact on the prevention of diabetes.