Clinical efficacy of a medically supervised low-calorie diet program versus a conventional carbohydrate-restricted diet.

Objective: To determine the effectiveness of a 6 month intensive medical intervention (IMI) with caloric restriction and high-protein meal replacements versus a conventional carbohydrate-restricted (CCR) diet. Methods: This is an observational study designed to determine weight outcomes at 6, 12, 18 and 24 months after completing the IMI or CCR treatment. Patients were also required to participate in at least 5 miles of walking and 240 minutes of overall exercise per week. The primary outcome was percent body weight loss (BWL). Results: A total of 604 patients with obesity or overweight were studied. Sixty-seven percent were in the IMI group, versus 33% in the CCR group. Initial BMI was similar in both groups (36.4 kg/m2 (SD=7.7) vs. 36.0 kg/m2 (SD=7.8), p=0.608). At 6 months, the IMI group had superior body weight loss (11.9% (SD=7.4) vs. 6.0% (SD=6.1), p<0.0001). However, the IMI group had greater weight regain than the CCR group, resulting in similar weight loss at two years (7.1% (SD=10.2) vs. 8.1% (SD=6.3), p=0.735). An adjusted analysis of outcomes averaged across 2 years demonstrated 2.8% greater BWL among the IMI group. Blood pressure significantly improved in both groups (p<0.001). Males (OR=1.77, 95% CI=(1.10,2.84), p=0.019) and patients with BMI ≥ 35 kg/m2 (OR=3.32, 95% CI=(1.95, 5.65), p<0.0001) were more likely to achieve weight loss success with the IMI. Conclusion: An Intensive Medical Intervention (IMI) characterized by high-protein meal replacements and caloric restriction can be highly effective in reducing body weight, even at two years post-intervention. This type of intervention should be strongly considered among obese patients who do not qualify for bariatric surgery, those with contraindications to weight loss medications, or those in need of weight loss prior to a medical procedure.