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Mission Nutrition for Combat Effectiveness. Overview. Nutritional Readiness Before Missions Sustained Night Operations Nutritional Readiness During Missions Missions in the Heat Missions in the Cold Missions at Altitude Missions in Water and at Depth Mission Scenarios.
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Overview • Nutritional Readiness Before Missions • Sustained Night Operations • Nutritional Readiness During Missions • Missions in the Heat • Missions in the Cold • Missions at Altitude • Missions in Water and at Depth • Mission Scenarios
Nutritional Readiness Before Missions • Maximize glycogen stores • Low glycogen stores = fatigue • Eat 2 - 4g of CHO/pound weight 3 - 4 hrs before an operation • Consume at least 400 g CHO/day • Minimize fat intake • Be well-hydrated
Sustained Night Operations • Sustained Operations (SUSOPS) • Work periods of ≥ 12 hours • Expect physical and mental fatigue, sleep loss • Continuous Operations (CONOPS) • Expect periods of uninterrupted activity followed by some sleep • Missions include SUSOPS and CONOPS • Expect fatigue and sleep deprivation
Sustained Night Operations • Nutritional Concerns • CHO intake • Maintain hydration status • Monitor caffeine intake
Energy Intake and SUSOPS • 50–70% of energy from CHO • 10-20% of energy from protein • 20-35% of energy from fat • Consume high CHO snacks and/or CHO-containing fluid replacement beverages • To maintain blood glucose and delay fatigue
Tryptophan and SUSOPS Avoid foods high in the amino acid tryptophan, which promotes sleep
Hydration and SUSOPS • Adequate intake of water is ~3.7 L (almost a gallon)/day • Beverages consumed should be ≤ 8% CHO (< 19g/8oz or 80 grams/L) • SOF operators need a lot of water
Caffeine and SUSOPS • Increases alertness and may delay fatigue • Common dose effective for maintaining performance and vigilance is 200 mg • “Stay Alert” gum in the Military contains 100 mg per chicklet • Current recommendation: 2 chicklets every 2 hrs • Effects of caffeine wears off within 6 hrs • Factors causing variability in effective dose • Habitual caffeine intake • Sensitivity to caffeine
Nutritional-Related Issues During Missions • Inadequate ration consumption • Inadequate energy intake • Dehydration • Gastrointestinal complaints
Rations and Mission Readiness • Inadequate ration and energy intake • Causes • Monotony • Lack of time • Results • Weight loss • Fatigue • Prevention • Consume as much of each part of) the ration as possible to maximize nutrient intake for performance
Dehydration and Mission Readiness • Causes • Occurs in any condition/environment if sweat and urine losses are not replaced by fluids • Consequences • Decreased appetite • Lethargy • Prevention • Drink about 4L of fluid per day • Drink more when environment is hot
Gastrointestinal Complaints During Missions • Causes • Stress/Changes in diet • Dehydration • Too much fiber • Poor sanitary conditions • Contaminated food • Unfamiliar bacteria • Prevention • Stay hydrated at all times • Avoid non-issue foods whenever possible
Missions in the Heat • Maintain fluid and electrolyte balance by: • Knowing temperature and humidity • Adjusting work rate • Being acclimated • Being aware of rate and volume of fluid intake • Monitoring urine color • Energy intake by 10% when working and living in 86 to 104 °F (30-40°C), unless activity level decreases accordingly
Hydration and Missions in the Heat • Dark yellow (7 - 9) and smelly urine suggest dehydration • B vitamins may cause urine to be bright (not pale) yellow, regardless of hydration status • fluid consumption until urine becomes pale yellow (1 - 3)
Electrolytes and Missionsin the Heat • Excessive loss of electrolytes through sweat may result in: • Muscle cramps • Severe medical problems • Preventive measures during and after missions: • Eat snacks with sodium and potassium • Consume fluids with electrolytes • Consider electrolytes in SportStrips and gels • Eat foods naturally high in sodium (salt) and potassium (dried foods)
Missions in the Cold • In cold environments, blood vessels tighten to conserve heat and shivering is initiated to generate heat resulting in: • Increased urine output • Increased energy metabolism • Nutritional considerations • Energy intake • Glycogen stores • Fluid status • Vitamin and mineral needs
Energy Intake and Missions in the Cold • Energy requirements can increase 25-50% during cold weather operations as compared to warm weather operations • Factors that increase caloric intake: • Added exertion due to wearing heavy gear • Shivering • Traveling over snow and icy terrain • Increased activity to keep warm
Energy Intake and Missions in the Cold • Fat and CHO are critical energy sources! • 50-60% of energy from CHO • 30-35% of energy from fat • 10-20% of energy from protein • High protein diets are not advised • Increase fluid requirements • Ingest foods that produce heat • CHO produces more heat than fat or protein • Hot beverages increase body temperature
CHO and Missionsin the Cold • Glycogen stores • A minimum of 400 grams of CHO per day is necessary in cold weather
Fluids and Missionsin the Cold • Dehydration common in cold weather: • urine output • fluid loss through breathing • Involuntary reduction in fluid intake • Sweating • Hence, drink plenty of water
Vitamins and Minerals and Missions in the Cold • Higher requirements for some vitamins and minerals due to: • energy metabolism (e.g. thiamin) • urinary loses (magnesium, zinc) • Prevention • Eat all ration components
Missions at Altitude • Major nutritional concerns • Weight loss • CHO intake • Dehydration • Oxidative Stress
Weight Loss and Missions at Altitude • Altitudes < 5,000m: weight loss can be prevented by eating on a regular basis • Altitudes > 5,000m: a 5-10% weight loss is unavoidable, but intake critical • Energy requirements may increase 15-50% above requirements at sea level • Energy intake should range from 3,500-6,000 kcal per day (i.e. at least 4 MREs or 2 First Strike Rations per day)
Weight Loss and Missions at Altitude • energy needs to 115-150% of sea level • sense of taste, which food intake • Changes in metabolism of fat and CHO • Loss of body water from breathing and dry air • Impaired absorption of nutrients • Acute Mountain Sickness (AMS) • Nausea, vomiting, headache, and appetite
CHO Needs and Missions at Altitude • Repletes glycogen stores • Requires less oxygen than fat to yield energy • Is most efficient energy source • Can blunt/delay progression/severity of AMS • Maintains blood glucose CHO must contribute to 50-70% of total energy or at least 400g of CHO per day
Dehydration and Missions at Altitude • respiratory losses due to ventilation • urine output due to altitude and cold temperature • Possible diarrheal fluid losses • Failure to drink water • Poor access to water Maintain a drinking schedule and monitor hydration status daily to avoid AMS
Oxidative Stress and Missions at Altitude • formation of reactive oxidative species • metabolic rate • Hypoxic conditions • Preventive measures • Vitamin E (400 IU/day) • A combination of 500mg of Vitamin C, 200 IU of Vitamin E, and 300 mg of alpha-lipoic acid in the morning and evening may be effective • Excessive use of antioxidants may be harmful!
Missions in Water and at Depth • Energy intake • Fluid intake • Mineral balance • Antioxidant balance
Energy and Missions in Water and at Depth • Increased energy expenditure due to: • Greater resistance offered by water • efficiency of movements when thermal protective clothing is worn • Preventive measures • CHO intake before an anticipated dive • Ingest CHO beverage or sports bar
Hydration and Missions in Water and at Depth • Fluid losses • Immersion in water urinary excretion 2-10x above normal • Preventive measures • Drink fluids before and after diving; • Consume beverages should with CHO when dives are longer than 2 hr
Missions in Water and at Depth • Mineral balance • urinary losses of Mg, Ca, Zn, and Cr • Preventive measures: • Consume foods containing these minerals • Antioxidant losses • Diving formation of reactive oxygen species • depth = O2 tension • Preventive measures • Take 1g of vitamin C and 400 IU of vitamin E 2 hrs before extended dives • Consume a diet high in natural antioxidants
Mission Scenarios • Performance can be sustained for weeks if: • Energy intake > 2000kcal/day • CHO intake ≥ 300 g • Protein intake ≥ 60 g • Fluid status is maintained • Sample nutritional plans in SOF manual • Typical training day • SDV Operations • Unconventional Warfare • Special Reconnaissance • Nighttime Air Mission
Key Points • Primary ways to be nutritionally prepared for all missions • Eat a high CHO diet • Be well hydrated • Eat CHO snacks every 2 to 3 hours to maintain blood glucose