Not Eating Enough Overcoming Underconsumption of Military Operational Rations (1995) / Chapter Skim
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19 From Biologic Rhythms to Chronomes Relevant to Nutrition
19 From Biologic Rhythms to Chronomes Relevant to Nutrition
Pages 361-372
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From page 361... ...
Shifts in meal timing have different effects upon different physiologic variables and thus alter internal relations among rhythms at different organization levels, as documented for the 55455 Franz Halberg, University of Minnesota, Chronobiology Laboratories, Minneapolis, MN 361
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From page 362... ...
FIGURE 19-1 Differential displacement of circadian hormonal timing as a result of changing a single daily meal from breakfast to dinner. Whereas the circadian rhythm of circulating cortisol is only slightly affected by the timing of a single daily meal, considerable phase-shifts are observed for the case of growth hormone, insulin, and glucagon.
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From page 363... ...
363 ~ G A OOooo /.
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From page 364... ...
, used with permission. gain in body weight at dinner only versus breakfast only (a statement equivalent to that of a relative body weight loss on breakfast only versus dinner only)
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From page 365... ...
Timing the Kinds of Calories Specifically, if one had the means, one should repeat the single meal per day study with and without exercise while concomitantly varying the proportions of carbohydrate, fat, and protein, both in the absence of snacks and then with the stepwise systematic addition of timed snacks. With more modest resources, the next step should be tests in the field with exercising and nonexercising individuals consuming three MREs as breakfast, lunch, and dinner versus consuming one-half of an MRE for breakfast, the other one-half MRE for lunch, and two MREs for dinner.
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From page 366... ...
Only one volunteer gained weight on breakfast versus dinner. Overall, the difference in relative body weight loss on breakfast (B)
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From page 367... ...
Therefore, to minimize body weight loss when a single meal is consumed, it may be preferable not to fix the ration but to offer a choice. An overall summary of relative body weight loss on breakfast only versus dinner only in the two studies described in Figures 19-4 and 19-5 indicates that the decrease in relative body weight was more pronounced when a fixed 2,000 kcal meal was imposed than when volunteers could choose what they ate.
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From page 368... ...
RECOMMENDATIONS Analysis of Available Data Current data suggest that a major meal should be eaten upon conclusion of a daily tour of duty; that is, if the duty starts in the morning, the major meal should be in the evening, or vice versa. In other words, scheduling should be by activity time rather than clock hour.
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From page 369... ...
Such differences as a function of family history of cardiovascular diseases are found early in life: shortly after birth and in adolescents. An unduly amplified circadian rhythm of blood pressure can be interpreted as presenting a heightened risk for vascular disease, notably stroke and nephropathy (Otsuka, 1994~.
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From page 370... ...
The risk indices reflected by the pattern of blood pressure variation could thus be correlated with left ventricular mass and other indices of the heart morphology obtained by echocardiography (Cornelissen et al., 1994; Kumagai et al., 1992~. If, in addition, the recruits can be persuaded to keep a precise diary of when and what they eat, it might be possible to study associations between any alteration of the cardiovascular chronomes and patterns in the relative consumptions of carbohydrate, fat, protein, and/or dietary supplements.
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From page 371... ...
Haus, and M Apfelbaum 1976 Timing of single daily meal influences relations among human circadian rhythms in urinary cyclic AMP and hemic glucagon, insulin and iron.
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From page 372... ...
Halberg 1993 Circadian stage-dependence of acetyl-L-carnitine effects on blood pressure and heart rate clinically healthy subjects. Chronobiologia 20:63-76.
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