14
Nutrition
Structured Meal Replacement Programs
• Replacing meals with medically predetermined shakes or bars to control
calories, micronutrients, and macronutrients
• Must be conducted with the guidance of a clinician or registered dietician
• Greater weight loss compared to control conditions at one and three years
Very Low-Calorie/Very Low-Energy Dietary Pattern (VLEDs)
Typically, caloric intake is less than 800 kilocalories (kcal)/d
but exceeds 200 kcal/d, necessitating medical supervision. This
approach is generally implemented using specially formulated
meal replacement products that deliver essential nutrients,
including protein, minerals, trace elements, and vitamins, under
the guidance of a trained clinician. This regimen is intended for
short-term application and requires close monitoring by both a
clinician and a registered dietitian.
Weight Reduction Metabolic Effects
• Produces more rapid weight
loss than low-calorie (low-fat or
carbohydrate-restricted) diets due
to lower energy intake
• Rapid weight loss occurs in a two-
to three-month period
• Often used for a shorter duration
• Beneficial before bariatric surgery
• Reduces fasting glucose, insulin,
and triglycerides
• May modestly increase high-
density lipoprotein cholesterol
levels
• May modestly decrease low-
density lipoprotein cholesterol
• Reduces blood pressure
Risks
• Fatigue, nausea, constipation, diarrhea, hair loss, brittle nails, cold
intolerance, dysmenorrhea may occur
• Small increased risk of gallstones, kidney stones, and gout flare
• Monitor for hypoglycemia and hypotension in patients treated with
medications for diabetes mellitus and hypertension; adjust medications
as needed
• Potential insuff icient micronutrient intake, which may predispose
to cardiac dysrhythmias and muscle cramps; consider screening for
vitamin D, iron, thiamine, folate, and vitamin B12 def iciency
• Weight regain will occur if patients are not taught how to maintain
healthy eating when transitioning to non-meal replacement
