Transcript Document

Mission Nutrition for
Combat Effectiveness
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
Sustained Night
Operations
• Nutritional Concerns
–  CHO intake
– Maintain hydration status
– Monitor caffeine intake
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
Tryptophan
and SUSOPS
Avoid foods high in the amino acid
tryptophan, which promotes sleep
Foods High in Tryptophan
Dairy products and eggs
Seafood
Poultry
Soy products
Whole grains
Rice
Meats
Hazelnuts, Peanuts
Sesame and
sunflower seeds
Beans and Lentils
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
Nutritional-Related
Issues During
Missions
• Inadequate ration
consumption
• Inadequate energy
intake
• Dehydration
• Gastrointestinal
complaints
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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)
Deuster/Kemmer/Tubbs/Zeno
Electrolytes and
Missions
in 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)
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
CHO and Missions
in the Cold
• Glycogen stores
– A minimum of 400
grams of CHO per day
is necessary in cold
weather
Deuster/Kemmer/Tubbs/Zeno
Fluids and Missions
in the Cold
• Dehydration common in cold
weather:
–  urine output
–  fluid loss through breathing
– Involuntary reduction in fluid intake
– Sweating
• Hence, drink plenty of water
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
Missions at
Altitude
• Major nutritional
concerns
–
–
–
–
Weight loss
CHO intake
Dehydration
Oxidative Stress
Deuster/Kemmer/Tubbs/Zeno
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 3,5006,000 kcal per day (i.e. at least 4 MREs or 2
First Strike Rations per day)
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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!
Deuster/Kemmer/Tubbs/Zeno
Missions in Water
and at Depth
•
•
•
•
Energy intake
Fluid intake
Mineral balance
Antioxidant balance
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno
Nutrition Requirements
Planning Guide
Deuster/Kemmer/Tubbs/Zeno
For Monitoring
Dehydration
Deuster/Kemmer/Tubbs/Zeno
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
Deuster/Kemmer/Tubbs/Zeno