So Datrex gives you a calorie ratio much better suited to an active survival situation, especially if water is scarce.  If you are certain that your situation will be cold and stationary, Skippy might be a better choice.  But IMO food with a profile similar to Datrex is a better fuel.  
 
Excellent research! I always get into trouble on this forum when I'm on vacation and it's raining.
What if I put the PB on hardtack or a cracker? Got carbs and still way cheap.
Nutrition Facts  
Serving Size 1 saltine cracker  
Amount Per Serving 
Calories from Fat 3
Calories 13  
% Daily Values* 
Total Fat 0.34g  1% 
  Saturated Fat 0.05g  0% 
  Polyunsaturated Fat 0.037g    
  Monounsaturated Fat 0.21g    
Cholesterol 0mg  0% 
Sodium 32mg  1% 
Potassium 5mg    
Total Carbohydrate 2.13g  1% 
  Dietary Fiber 0.1g  0% 
  Sugars 0.01g    
Protein 0.28g