Liquid Diet

A few days before Christmas 2003 I had my mouth wired shut after having surgery on my jaw. I was on a liquid diet for a week and then I graduated to things like jello. I am here to tell you that you can only drink so much chicken broth before your body starts screaming "Give me a steak!" and I still gag when I think about drinking Ensure. Remembering this episode got me wondering if it is possible to survive solely on pure chemicals? While searching the literature I found out not only that it is possible but what the perfect recipe is. In a paper entitled "Evaluation of Chemical Diets as Nutrition for Man-in-Space1" Winitz et al inform us that the perfect diet is:

l-Lysine·HCl 3.58 g
sodium l-aspartate 6.40 g
l-Leucine 3.83 g
l-Threonine 2.42 g
l-Isoleucine 2.42 g
l-Proline 10.33 g
l-Valine 2.67 g
Glycine 1.67 g
l-Phenylalanine 1.75 g
l-Serine 5.33 g
l-Arginine·HCl 2.58 g
l-Tyrosine ethyl ester·HCl 6.83 g
l-Histidine·HCl·H2O 1.58 g
l-Tryptophan 0.75 g
l-Methionine 1.75 g
l-Glutamine 9.07 g
l-Alanine 2.58 g
l-Cysteine ethyl ester·HCl 0.92 g

Water-soluble vitamins
Thiamine.HCl 1.00 mg
d-Biotin 0.83 mg
Riboflavin 1.50 mg
Folic acid 1.67 mg
Pyridoxine.HCl 1.67 mg
Ascorbic acid 62.50 mg
Niacinamide 10.00 mg
Cyanocobalamin 1.67 mg
Inositol 0.83 mg
p-Aminobenzoic acid 416.56 mg
d-Calcium pantothenate 8.33 mg
Choline bitartrate 231.25 mg

Potassium iodide 0.25 mg
Potassium hydroxide 0.83 g
Manganous acetate 18.30 mg
Magnesium oxide 0.38 g
Zinc benzoate 2.82 mg
Sodium chloride 4.77 g
Cupric acetate 2.50 mg
Ferrous gluconate 0.83 g
Sodium glycerophosphate 1.67 mg
Calcium Chloride·2H2O 2.44 g
Ammonium molybdate·4H2O 5.23 g
Sodium benzoate 1.00 g

Glucose 555.0 g
Glucono-δ-lactone 17.2 g

Fats and fat-soluble vitamins
Ethyl linoeate 2.0 g
α-Tocopherol acetate 57.29 mg
Vitamin A 3.64 mg
Menadione 4.58 mg
Vitamin D 0.057 mg

They point out that these diets are unique because " (a) their essential and nonessential nitrogen is provided in the form of highly pure L-amino-acids; (b) the are administered as single, crystal clear solutions which are nutritionally complete in themselves"

The dry ingredients were dissolved in distilled water to give a solution of 50-75% solids by weight which was completely sterile and had about 2-3cal per mL and could be stored almost indefinitely.

24 inmates from the California Medical Facility volunteered to drink/eat nothing but this liquid diet for 19 weeks. They were allowed to drink as much as they wanted and they could have all the water they wanted too. I can understand why they needed to use inmates because if they were on the outside after a week or so a cheeseburger looks really good.

They found that this diet provided well for these inmates and that there were no ill effects on their health. The authors go on to explain that these diets overcome some of the limitations inherent in alternative space-food sources:
"[These diets provide] high nutritive efficacy in ultra-compact form-1 ft3 of the diet as a 75% solution in water, will provide a 154-lb astronaut with all his required essential and nonessential nitrogen, salts, vitamins, and fats, in addition to his estimated requirement of 2,830 calories per day, for a period of a month; (b) complete water solubility- provides advantages in the administration of the diets in liquid form under conditions that will not permit the use of solids; (c) low bulk reduces low faecal residues and mitigates the critical problem of disposal of solid wastes; (d) complete nutrilite accessibility-allows alteration at will of the amino-acid ratios, carbohydrate content, and levels of all other components, thereby making it possible to tailor formulations to specific dietary needs of individual astronauts; (e) complete digestibility- provides dietary components in the most elemental form in the event of disturbances of the digestive system; (f) good storage stability either in the solid state or as aqueous solution."

This might be worth looking at for food storage...
1Winitz, M.; Graff, J.; Gallagher, N.; Narkin, A.; Seedman, D. A.; Nature 1965, 205, 741-743

1 comment:

Nagesh Shukla said...

thanks for the informative post.This was very helpful to me
Keep it UP!!!
Thanks and Regards,