Why do physicians recommend high protein diets for medical and surgical weight loss patients?

Studies have shown that patients who consume a high protein, low carb diet have less hunger as they go through their weight loss process.  Proteins seem to suppress hunger and cravings.  Carbohydrates and sugar on the other hand seem to stimulate hunger and cravings.  Another reason why physicians recommend higher levels of protein during the active weight loss phase of a diet is that during rapid weight loss many individuals tend to lose lean body tissue including muscle mass along with fat and water loss, which results in a reduce metabolic rate since muscle mass determines in a large part our basal metabolic rate or the rate at which we burn calories at rest.  This loss of lean body tissue which often happens with rapid weight loss where adequate protein intake and resistance exercise is not part of the active weight loss treatment program will often result in patients actually regaining more weight than they lost from the diet because their metabolic rate is lower after the diet than before the diet.  So it is very important that during the active weight loss phase of your weight loss program that adequate protein intake and resistance exercise is integrated into the program to preserve lean body tissue and basal metabolic rates to prevent this potential complication and weight regain effect.

In some weight loss programs called VLCD (very low calorie diet) the protein to carbohydrate ratio may be 2:1, but in most cases bariatric (weight loss) physicians recommend a 1:1 ratio of protein to carbohydrate during the active weight loss phase.   In these diets patients aren't actually taking in any more protein than they would normally, they are simply reducing their carbohydrate levels to meet the 1:1 ratio.  

Patients over time develop 'taste fatigue' by consuming only animal based proteins and choose to utilize proteins in supplemental forms such as protein shakes and bars which can deliver the protein in a very palatable and efficient form.  Protein supplements are the cornerstone of most physician supervised weight loss programs and have been found to help patients stay compliant to the high protein demands of weight loss programs to achieve greater overall weight loss.

For bariatric surgical patients the emphasis is on 'protein first' that is, patients are encouraged to get adequate protein into their diet before they consume any other foods.  Lap-band patients are encouraged to consume 45 grams of supplemented protein daily and those who undergo gastric bypass 60 grams of supplemented protein daily before the eat any other food.  These patients are also at risk for vitamin and mineral depletions which must be supplemented along with adequate protein supplementation.