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Some Dietary Issues in Exercise: Weight Control

Some Dietary Issues in Exercise: Weight Control. Maintaining adequate nutritional status is not much of a problem for healthy & active individuals who eat reasonably well . . . Things are different, however, when restricting calories . . .

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Some Dietary Issues in Exercise: Weight Control

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  1. Some Dietary Issues in Exercise: Weight Control

  2. Maintaining adequate nutritional status is not much of a problem for healthy & active individuals who eat reasonably well . . . Things are different, however, when restricting calories . . .

  3. With the Estimated Energy Requirement (DRI) for Adolescents & Adults being so much higher than the caloric intake necessary to get the minimum nutrients . . . Males (9 yrs – 13 yrs ~ 2250) 14 yrs – 18 yrs ~ 3150 19 yrs – 50 yrs ~ 3050 - subtract 10 kCal / day for each year over 19 yrs Females (9 yrs – 13 yrs ~ 2100) 14 yrs – 18 yrs ~ 2350 19 yrs – 50 yrs ~ 2400 - subtract 7 kCal / day for each year over 19 yrs

  4. Remember This Healthy Diet Concept: Number of Food Servings for Daily Caloric Intakes: Food Group Standard Approximate ~ 2000 ~ 2200 ~ 2500 ~ 2800 Serving Size Calories / kcal kcal kcal kcal Serving Fruits0.5 cup 71 5 5 5 5 Vegetables0.5 cup 38 6 6 6 6 Cold-Water Fish4 ounces 120 2/wk 2/wk 2/wk 2/wk (Lean Meats on 3 ounces 120 - - - - remaining days are optional) Nuts & Seeds 0.25 cup 240 1 1 1 1 Beans & Legumes0.5 cup 110 2 3 3 3 Dairy1.0 cup/2 oz. 86 3 3 3 3 Breads & Cereals1 slice/1 oz 78 5 6 7 7 Red Wine4 oz 85 1 1 1 1 Added Fats1 Tbsp (EVOO) 110 2 2 3 3 Discretionary Calories - - 200 400 *1900/2000 kCal intake meets RDA requirements on average; 2200 kCal or more meets or exceeds requirements each day. . . So it just shouldn’t be so difficult

  5. Adapted from: Nutrition for Sport and Exercise, Dunford & Doyle, 2008 Unfortunately . . . the average non-restricted American diet really sucks . . . especially in the area of fruits and vegetables; major sources of many vitamins and minerals . . .

  6. Resulting in an almost non-existent probability of being adequate . . . especially with a calorie-restricted diet!!! Adapted from Nutrition for Sport and Exercise, Dunford & Doyle, 2008

  7. Because we really really like to go on weight loss-loss diets . . . And lose weight as fast as possible . . . It is not unusual for us eat 1,000 or 1,200 kCals each day while trying . . . Vitamins and minerals are already a “lost cause”, but even the minimum requirements for the major macronutrients (CHO, AA, FFA)can be at risk . . .

  8. AI 130 g/day 45% to 65% of total calories (4 kcal/g) IOM recommends 1 hour of moderately stressful exercise every day NRG for moderately stressful exercise is 50 – 80% carbohydrate . . . 6 – 7 mph ~ 600 – 800 kcals @ ~50% ~ 300 – 400 kcals = ~ 75 – 100g additional CHO Therefore, a logical minimum DRI would be more than the IOM recommendation ~ 200g/day would be a reasonable estimate

  9. AI 0.8 g/kg; 1.0 - 1.4 g/kg with exercise 10% to 35% calories (4 kcal/g) Nitrogen balance studies indicate that more is needed with exercise . . . . . . labeled infusion studies on the use of amino acids for synthesis and metabolism indicate a decrease in proteolysis / with a maintenance of synthesisfollowing repeated exercise; leading to a reduction in the dietary protein requirement . . . Therefore the IOM recommendation for 1.2 – 1.4 g/kg with moderate to stressful exercise may be somewhat dubious & Because average American consumes > 2X DRI already, modifying dietary content of protein also is of dubious benefit…

  10. AI 12 & 17 g/day linoleic acid (C18:2; n6, 9 - all cis): F / M; based on on median intake 1.1 & 1.6 g/day α-linolenic acid (C18:3; n9, 12, 15 - all cis) F / M; based on median intake Or: 10 - 35% of total calories (9kcal/g)… so… lets see what you have to eat to… Some older texts suggested a minimum total intake of 20g/day to insure a sufficient uptake of fat soluble vitamins which greatly underestimates the actual dietary lipid requirement (RDAs are based on fatty acid intake, not TG intake and eating exactly 12g linoleic acid or 1.1 g α-linolenic acid would obviously necessitate eating more than 13g total fat since the EFA are a small minority of total FFAs) EFA Content of various foods in % of total FA Linoleic α-Linolenic % Fat by Wt Canola Oil ~ 26 - 100 Corn Oil ~ 35 - 65 - 100 Olive Oil ~ 3 - 20% ~ 1% 100 Palm Oil ~ 6 - 12 ~ 0.5 100 Peanut Oil ~ 14 - 43 ~ 0.4 100 Flax Oil ~ 14 ~ 50 - 60 100 Beef (grain-fed-trimmed) ~ 3.4 ~ 0.4 ~ 5 Beef (grass-fed-trimmed) ~ 4.4 ~ 1.2 ~ 2.5 Chicken (skinless-breast) ~ 21 ~ 0.9 ~ 4.5 Salmon (Norway-wild) ~ 1 ~ 1 (2%EPA/20% DHA) ~ 3 - 4 Human Milk ~7 - 18 ~ 1 ~ 2 - 4 Cow Milk Fat ~ 2.6 ~ 1.6 ~ 0, 1, 2, or ~3.5 Based on the EFA content of common foods (as a percent of total fatty acids) you clearly have to eat a lot more grams of fat than the RDA (as expressed in grams for the EFA’s) – 60 g/day would not be an outlandish minimum estimate.

  11. Summary Minimum Macronutrient Intakes: Carbohydrate: ~ 200g/d = 800 kCal Protein: ~ 0.8 g/kg/d (~60 g?) = 240 kCal Lipid: ~ 60 g/d = 540 kCal Total kCal = 1580 At 1900 kCal (following the recommended servings):Recommended % (IOM) carbohydrate = ~ 250g (55%) 45% - 65% protein = ~ 70g (16%) 12% - 20% lipid = ~ 60g (30%) 20% - 35% At 1200 kCal (cutting the recommended servings to exactly 63%): carbohydrate ~ 157g protein ~ 44g lipid ~ 37g At this intake, protein is below the minimum AI for a sedentary person . . . And carbohydrate is below the minimum recommended for an active person . . . And fat is below a “reasonable minimum”…

  12. Obviously, the “average” American who attempts a weight-loss diet will be deficient in something in a very short time - especially if they go on one of those fad diets that severely restrict one of the major macronutrients; such as the Atkin’s diet. The best solution is to first revise the diet to be consistent with the recommended array of servings: See recommended servings for. . . And then introduce physical activity (500 kCal minimum) . . . And then monitor weight and skinfolds . . . And then figure out what to do; adjust servings (trial & error) . . .

  13. Number of Food Servings for Different Daily Caloric Intakes ________________________________________________________________________________________________________________ Standard Average *Required Recommended Serving kcal/ Food Group Size Serving ~1900 kcal ~2200 kcal ~ 2500 kcal ~ 2800 kcal ________________________________________________________________________________________________________________ # Servings ____________________________________________________ Fruits 0.5 c. 71 4 4 5 6 Vegetables dark green 0.5 c. 20 2 2 3 3 deep yellow 0.5 c. 38 1 1 2 2 starchy 0.5 c. 76 1 1 1 2 other 0.5 c. 18 2 3 3 3 Meat/Fish/Eggs 3 oz. 165 0 1 1 1 Beans/Legumes 0.5 c. 110 2 3 3 3 Nuts/Seeds 0.33 c./0.25 c. 240 1 1 1 1 Dairy (skim/low-fat) milk/yogurt 1 c. 86 3 3 3 3 cheese ~ 2 oz. Breads/Cereals 0.5 c. 78 5 6 7 9 (whole grain/fortified) 1 slice Added Fats 1 Tbsp. 100 2 2 2 3 *Red Wine 4 oz. 85 1 1 1 2 ________________________________________________________________________________________________________________ The ~1900 kcal recommendation follows the minimum required number of servings from each food category as described in the Optimal Health Guide. Caloric values are based on the tabled values for nutrient and caloric content of food servings available in the 2005 IOM and USDA recommendations. These values are based on averaged values from mixed food servings from the North American diet and should be considered to be reasonable estimates. *Can safely be removed from the minimum without compromising nutrient intake to produce a ~ 1800 kcal intake.

  14. Calories Burned For 30 Minutes Exercise* ________________________________________________________________________________________________________ Exercise Approximate Calories Burned for the Indicated Body Weight Intensity ________________________________________________________________________________________________________ 110 lbs 150 lbs 190 lbs _____________________________________________ Bicycling Hard (fastest possible) 255 350 445 Moderate (~ 10 mph) 165 225 285 Easy (~ 5 mph) 90 120 152 Running 10 mph 415 565 715 8 mph 350 475 600 6 mph 265 360 455 Weight Lifting Hard 175 240 305 Moderate 130 175 225 Stationary Rowing Hard 270 370 465 Moderate 180 245 310 Aerobics Hard 205 280 350 Moderate 165 225 285 Swimming Hard 550 750 950 Easy 165 225 285 Basketball Moderate 150 205 260 Golf Carrying 130 180 225 Cart 110 150 190 Rollerblading Hard 270 370 465 Moderate 235 320 400 Walking 4.5 mph 170 235 295 3.5 mph 125 175 220 2.5 mph 95 130 165 ________________________________________________________________________________________________________ *Please note that these caloric-expenditure values are approximate only. Everyone is different and some people may burn as much as 15% fewer than these values or 15% more than these values and the value amountwill changewith training & diet.

  15. Be absolutely “anal” about counting & measuring servings and tracking your minutes of exercise activities every day. After a few weeks you will have a good idea about your estimated average calorie intake and your estimated average exercise calorie output. Try moving toward the minimum-servings diet plan… as long as you stay near the minimum servings/day (w/o wine) your intake will be around 1800 kcal/day and developing a nutritional deficiency will be minimized. See what happens… Adjust exercise minutes and/or servings every couple weeks to see what happens & to produce a weight-loss of no more than 2 pounds/week - there should be no hurry!

  16. Too Much - Too Fast! 2000 kcal/day Caloric Deficit Week Body Mass % Body Fat Total Fat Fat Loss Lean Loss 0162 18% 29.16 lbs - - 1158 17% 26.86 2.30 lbs 1.70 lbs 2154 15% 23.10 3.76 lbs 0.24 lbs 3 150 14% 21.00 2.10 lbs 1.90 lbs Total Fat & Muscle Loss ~ 12 lbs ~ 4 lbs/week Total Fat Loss ~ 8 lbs Total Lean Mass Loss ~ 4 lbs NOT really a good thing - Lose 8 lbs fat in 3 weeks and lose 4 lbs of indispensable tissue along with it!!

  17. 1000 kcal/day Caloric Deficit Week Body Mass % Body Fat Total Fat Fat Loss Lean Loss 0161 18% 28.80 lbs - - 1159 17% 27.03 lbs 1.77 lbs 0.23 lbs 2157 16% 25.12 lbs 1.91 lbs 0.09 lbs 3 155 15% 23.25 lbs 1.87 lbs 0.13 lbs 4 153 14% 21.42 lbs 1.83 lbs 0.17 lbs Total Fat & Muscle Loss ~ 8 lbs ~ 2 lbs/week Total Fat Loss ~ 7.4 lbs Total Lean Mass Loss ~ 0.6 lbs A much better result - Lose 7.4 lbs fat over 4 weeks and only 0.6 lbs of the good stuff

  18. Some Dietary Issues in Exercise: Negative Calorie Balance (Eating Disorders and Disordered Eating)

  19. Throwing stressful exercise into the mix seems to really screw things up . . . The Female Athletic Triad is a good example of how things appear to be something they are not: - Disordered eating - Amenorrhea - Osteoporosis Primary (ONLY?) cause is disordered eating

  20. Disordered Eating - Some Data: - low-energy diet ie. a negative energy balance: anorexia nervosa (1.3%), bulimia nervosa (8%), anorexia athletica (8.2%, of elite female athletes in 1993 Norwegian survey); 5.6% AN/NB in collegiate athletes with ~30% at risk in 2002 survey… Disordered eating is common in weight-sensitive sports: gymnastics, light-weight rowing, martial-arts, ballet, distance running, diving, figure skating … - eating disorders are usually considered obsessive: AN & BN are obsessive, disordered eating (AA) is usually not - chronic caloric deficits force physiological adaptation - chronic caloric deficits in face of “normal american diet” imply nutritional deficits as well - amenorrhea and osteoporisis result from the physiological adaptations to calorie (& nutrient) deficits

  21. Athletic Triad: presence of Disordered eating + Amenorrhea + Osteoporosis: - Elite athletes 4.3% (14 hours stressful exercise / week) - Active controls 3.4% (~ 5 hours exercise / week) Disordered eating + menstrual dysfunction: - Elite athletes: 26.9% - Active controls: 13.8% Disordered eating + low BMD - Elite athletes: 10.2% - Active controls: 15.2% Menstrual dysfunction + low BMD - Elite athletes: 5.4% - Active controls: 12.4% Add it all together and ~ 47% elite and ~ 45% control athletes could have a problem!

  22. Negative Energy Balance & Amenorrhea Eating insufficient calories leads to amenorrhea studies document women athletes who are amenorrheic eat the same or fewer calories each day than non-active women decreased T3 and Leptin are observed in women with “athletic- amenorrhea” and both are directly associated with negative caloric balance prolonged negative energy balance leads to decreased GnRH, LH, and ultimately: ovarian failure, resulting in lower estrogen levels and higher prolactin levels; both of which lead to amenorrhea

  23. The endocrine response to negative caloric balance also affects bone cells Reduced estrogen and enhanced cortisol are major endocrine responses to starvation that can directly effect bone cell function. Major bone cells: Osteoclasts: bone resorption Osteoblasts: bone deposition - bone remodeling: a couple weeks of resorption by osteoclasts which then die through apoptosis - followed by 3 – 4 months of new deposition by osteoblasts to fill in the cavity left by the osteocytes and then most die through apoptosis while some differentiate into osteocytes - it takes up to a few years for complete re-mineralization of the new bone.

  24. The endocrine response to negative caloric balance affects the bone cells Estrogen normally inhibits osteoclast function to limit the rate of bone resorption as well as the development of pre-osteoclasts into osteoclasts Estrogen also decreases local production of IL-6, IL-1, and TNF, all of which enhance the development of osteoclasts from precursor cells Therefore: Reduced estrogen due to starvation greatly enhances bone resorption (Add in a nutritional deficit from a lousy diet and you then have a real big problem!!)

  25. Cortisol levels increase as a result of a negative calorie balance in order to enhance gluconeogenesis . . . Cortisol also enhances rates of apoptosis in osteoblasts, reducing bone formation. Therefore; as a result of low estrogen and high cortisol, both of which are starvation responses, osteoporosis will develop . . . . . . So, lets look at some nutritional aspects of bone formation to see why osteoporosis is so common . . .

  26. Major Nutrients That Are Important For Bone Formation Include: Adult RDA or AI Median Intake (USA) - NHANESIII♂ ♀ ♂ ♀ Calcium teen 1300 mg 1000 mg ~ 1000* ~ 650 adult 1000 mg 1000 mg ~ 850 ~ 600 Phosphorus 700 mg 700 mg ~ 1450 ~ 1,000 Magnesium 18 – 30 yrs 400 mg 310 mg 9+ yrs 31 – 50 yrs 350 mg 265 mg ~ 310 ~ 220 Vitamin D 5 µg 5 µg n/a Vitamin K 120 µg 90 µg ~ 105 ~ 85 Vitamin C 90 mg 75 mg ~ 120 ~ 90 Vitamin A 900 µg 700 µg ~ 1,000RE ~ 800RE Zinc 11 mg 8 mg ~ 14 ~ 9 Copper 900 µg ~ 1400 ~ 1000 Iron 8 mg 18 mg ~ 17 ~ 12 *25+ % prevalence of deficient intake

  27. Major Nutrients That Are Important For Bone Formation include: Calcium : component of hydroxyapetite Phosphorus : component of hydroxyapatite Magnesium : necessary for binding of PTH to receptor & crystallization of matrix Vitamin D : 1,25 dOH-D3 (calcitrol): hormone to initiate transcription of Ca++- binding proteins Vitamin K : necessary co-factor for gamma-glutamyl carboxylase; post- translational modification for Ca++-binding properties (osteocalcin) Vitamin C : necessary co-factor for proline and lysine hydroxylase for procollagen synthesis Vitamin A : RxR binding and osteoclast maturation Zinc : a component of alkaline phosphatase that enhances microavailability of phosphorus for mineralization Copper : a component of lysyl oxidase for crosslinking of collagen fibers Iron : a component of lysine and proline hydroxylase for stabilization of procollagen synthesis collagen

  28. Hematopoietic Stem Cells: bone marrow stem cells that can differentiate into lymphocytes, granulocytes, monocytes, erythrocytes, osteoclasts . . .

  29. Mesenchymal Stem Cells: bone marrow stem cells that can differentiate into osteoblasts, chondrocytes, myocytes, adipocytes. . .

  30. From your extensive knowledge of nutrition stuff (including specific nutrient sources - that would be individual foods) be prepared to design food intake resource tables (specific foods, RDA/AIs, and food groups), to illustrate “how easy” it is to enhance calcium, magnesium, vitamin K, and iron in the diet for adult female athletes ... Oh yeah! . . . Include zinc and folic acid as well . . . Just for fun (see next) And oh yeah again . . . You may want to be the nutritionist and include specific functions of the nutrients in the same resource tables . . .

  31. Some Dietary Issues in Exercise: Anemias

  32. Anemias Iron deficiency can lead to anemia; a reduced volume of RBC’s in the blood with obvious implications for oxygen-carrying capacity of the blood and alterations in performance capacity . . . iron deficiency without anemia still reduces performance In addition to iron deficiency, anemias also are associated with vitamin B12deficiency, folic acid deficiency, or extensive RBC hemolysis (can occur with endurance running) Iron deficiency : microcytic anemia due to inability to anemia synthesize sufficient hemoglobin Symptoms include: fatigue / paleness / irritability / tachycardia / pica / sore & swollen tongue B12 and/or folic acid deficiency : macrocytic anemia due to insufficient anemia DNA synthesis for cell proliferation during hematopoesis Symptoms include: nausea / weakness / fatigue / numbness or tingling in hands and feet / decreased appetite & weight loss / diarrhea / tender tongue – not swollen

  33. Some Major Nutrients That Are Important For RBC Formation Include: Adult RDA or AI Median Intake (USA) - NHANESIII♂ ♀ ♂ ♀ Phosphorus 700 mg 700 mg ~ 1450 ~ 1,000 Magnesium 18 – 30 yrs 400 mg 310 mg 9+ yrs 31 – 50 yrs 350 mg 265 mg ~ 310 ~ 220 Zinc 11 mg 8 mg ~ 14 ~ 9 Iron 8 mg 18 mg ~ 17 ~ 12 Folic Acid 400 µg unknown / ~ 10% deficiency in USA B12 2.4 µg ~ 4.5 ~ 3 Choline 550 mg 425 mg unknown B6 1.3 mg ~ 1.9 ~ 1.5 *25+ % prevalence of deficient intake

  34. Some Major Nutrients That Are Important For RBC Formation include: Phosphorus : essential component of nucleotides Magnesium : necessary for (genomic) DNA synthesis and repair - facilitates binding Cobalamine (B12) : necessary for conversion of methyltetrahydrofolate to tetrahydrofolate Zinc : a component of delta-aminolevulinic acid dehydratase for heme synthesis, zinc-finger motifs of promoters Iron : necessary for heme synthesis Folic Acid : necessary for thymidylate synthesis (DNA synthesis) & methylation of t-RNA Choline : methyl transfer for betaine synthesis in B12/folate cycling for DNA synthesis B6 : a component of delta-aminolevulinic acid synthase

  35. (Production of Erythrocytes)

  36. In order for high rates of RBC synthesis to be maintained, high rates of DNA and protein (including hemoglobin) synthesis are necessary . . .

  37. You’ve seen this before . . . Only now it is labeled with some nutrient requirements

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