Obesity Case 2

A 47 year-old white man of Italian descent with a strong family history of type 2 diabetes and cardiovascular disease was recently diagnosed with prediabetes. He has always been proud that he does not have any chronic disease and has never needed to take any medications, despite having a weight problem. He does not follow any specific diet plan, but is very active. He is currently doing 150 minutes of moderate intensity physical activity every week. He cooks most of his meals and rarely dines out. His meals, in general, are high in carbohydrates as he loves pasta, pizza, and bread. He also adds olive oil to most of his meals and eats fatty fish two times per week. He does not eat much red meat, but eats a lot of processed meat and cheese. During his last visit to his primary care physician, his fasting plasma glucose was 110 mg/dL (normal, 70-100 mg/dL), and his glycated hemoglobin (HbA1c) was 6.1% (normal, <5.7%). He was shocked by the results. Except for obesity, he does not have any other health problems. When your dietitian reviewed his 3-day food log, she found that he consumes approximately 2800 calories per day with total carbohydrates comprising 60% of his diet.

  • Weight: 206 lbs (93.6 kg)
  •  Height: 67 inches (170 cm)
  • Body mass index (BMI): 32 kg/m2 (normal, 18.5 to 24.9 kg/m2)
  • Waist circumference: 40 inches
  • Blood pressure: 130/80 mm Hg
  • Low density lipoprotein cholesterol (LDL-C): 98 mg/dL (desirable, <100 mg/dL)
  • High density lipoprotein cholesterol (HDL-C): 42 mg/dL (desirable, ≥60 mg/dL)
  • Triglycerides (TG): 186 mg/dL (desirable, <150 mg/dL)

His internet search led him to read the results of the diabetes prevention program, which showed that weight loss reduces type 2 diabetes risk by 58%. He stated that he was in the best shape, and he would like to reach that goal over the next 8 weeks by reducing total caloric intake to 1000-1200 calories/day and increasing his activity to 50 minutes on 5 days of the week to a total of 250 minutes/week. He came to you for advice regarding healthy eating patterns and physical activity that will help him to prevent type 2 diabetes.

Question 1

In helping this individual to achieve and maintain his target weight loss, which of the following advice is BEST?

A. Losing 0.5 to 2 lbs (0.2-0.9 kg) per 1-2 weeks is acceptable and safe.
B. Reducing caloric intake to 1200 calorie is the fastest and safest way to achieve your goal of 10% weight loss in 8 weeks.
C. When reducing caloric intake to 1200 calories, people with obesity should increase protein intake to not less than 1.5 gm/kg per day of actual body weight.
D. Exercising 30 minutes per day on 5 days per week is adequate to prevent weight regain after weight loss.
E. A diet low in fat and relatively higher in carbohydrates is frequently better that a diet low in carbohydrates and higher in fat to achieve target weight loss.
Correct Answer
A. Losing 0.5 to 2 lbs (0.2-0.9 kg) per 1-2 weeks is acceptable and safe.

For weight management, consistency is more important than speed of weight changes. Weight losses of 0.5 to 2 lbs (0.2-0.9 kg) per 1-2 weeks are acceptable and safe. You can calculate basal metabolic rate (BMR) using the Harris-Benedict equations (For men BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) - (5.677 x age in years). The answer can then be multiplied by an activity factor (i.e., 1.375 for light exercise 1-3 days per week; 1.55 for moderate exercise 3-5 days per week). Using this patient as an example: BMR = 88.362 + (13.397 x 93.6) + (4.799 x 170) – (5.677 x 47) = (88 + 1254 + 816)-266 =  1892 x 1.55 = 2932- 500 = 2432 kcal. Thus, reducing caloric intake by 250-500 is reasonable and tolerated, making option A the correct response.Weight loss of around 7% significantly improves insulin sensitivity and helps individuals with prediabetes to prevent diabetes. A goal of 5-10% weight loss maintained for a year is an optimal target for patients with obesity and prediabetes.

For an individual who consumes 2800 calories per day, reducing caloric intake to 1200 calories per day may not be doable and is frequently associated with rapid weight regain.  Thus, option B is incorrect.

People who are overweight and obese may choose to increase the percentage of calorie intake from protein and decrease the percentage from carbohydrates to around 40-45% when they reduce caloric intake for weight reduction. It is particularly important to maintain the absolute protein intake at not less than 1.2 gm/kg of adjusted body weight when the total caloric intake is reduced to 1200-1500 calories to avoid protein malnutrition. Recommended protein intake is around 15-20% of total caloric intake. However, when caloric reduction is recommended for weight reduction, the use of percentages to calculate protein intake may result in a serious reduction in absolute protein intake. For this reason, individuals who seek weight reduction through caloric restriction should calculate protein intake based on gram/kg body weight. Adequate intake is 0.8 gm/kg of body weight, but for people who are overweight, 0.8-1.5 gm/kg of adjusted body weight [Adjusted Body Weight = IBW (Ideal Body Weight) + 0.25 (Current Weight - IBW) can be used to calculate appropriate intake. Thus, protein intake of 1.5 g/kg of actual body weight is too high, making option C incorrect.

Regular physical activity, including a balanced mix of stretching, cardiovascular exercise, and progressive resistance exercise for at least 30 minutes most days of the week, has health benefits and is needed to control body weight. Exercise has been shown to help overweight and obese patients to maintain weight loss over the long-term. About 60 minutes a day of moderate intensity exercise for at least 5 days/week (300 minutes/week) may be needed to prevent weight regain. Thus, option D is also incorrect.

Although a traditional weight loss diet is generally low in calories and fat, several meta-analyses comparing low-fat versus low-carbohydrates diets have consistently shown that a diet lower in calories and carbohydrates is superior to a diet low in fat and higher in carbohydrates. The percentage of carbohydrates in a weight loss diet should not be higher than 40-45%, but not less than 130 g/day. Carbohydrates of lower glycemic index like non-starchy vegetables, fruits, and whole grains are the preferred source of carbohydrates. Thus, option E is also an incorrect response.