Å spise ofte gjør ikke at du går ned mer i vekt eller får høyere fettforbrenning (1,2,3,16,17,20,23). Påstanden om at man må spise ofte for å "holde forbrenningen oppe" har ingen større vitenskapelig forankring.*
Forbrenningen vil ikke "stoppe opp" eller gå langsommere bare fordi man ikke spiser i løpet av noen timer. Snarere er det så at den vil kunne øke noe de første døgnene uten mat (5), og å faste i korte perioder (f.eks. annenhver dag eller større delen av dagen) for å deretter spise mer for å kompensere kaloriinntaket kan ha flere helsefordeler som f.eks. forbedret insulinfølsomhet (6,7), og kan fungere som en "Calorie Restriction Mimetic" (det finnes klare paralleller mellom kalorirestriksjon og lang levetid (7,9,10)) og dermed motvirke aldring og aldersrelaterte sykdommer som Alzheimers, Parkinsons og Huntingtons (8,9,10,11) samt minske risikoen for slag og hjerteinfarkt (9,10).
Kroppen vil heller ikke begynne å bryte ned muskelprotein i større mengder bare fordi man ikke spiser ofte (12,18), man må ikke tilføre protein ofte for å bygge muskler, og det finnes ingen direkte begrensninger på hvor mye protein kroppen kan ta opp ved et måltid (13,14). Et større måltid med mer protein bruker bare lengre tid på å fordøyes enn et mindre måltid.
* en studie som ofte trekkes frem som (mer eller mindre eneste) bevis for at en høy måltidsfrekvens er fordelaktig mtp fettforbrenning/muskler er den så kalte "bokser"-studien fra 1996 (21) hvor aktive og ikke overvektige boksere holdt en 1200 (!) kcal-diett, og dessuten med kun flytende (rask fordøyelig) føde. Begge gruppene mistet (selvsagt) mye muskelmasse, dog mistet de som fikk 2 shakes mer. Ikke så veldig rart da de fikk altfor lite og for raskt fordøyelig protein, altfor sjelden for å kunne å motvirke muskeltap. Hadde studien blitt utført med "ordentlig" mat hadde resultatet ikke blitt det samme, som i f.eks. Stote et al' sin studie fra 2007 (22) hvor de sammenlignet 1 vs 3 måltider (energibalanse, med fast føde). Hos de som spiste 1 måltid ble kroppsmassen omfordelt slik at de fikk lavere fettprosent og mer muskler enn de som spiste 3 måltider over de seks månedene som studien gikk over.
1. "The daily distribution of food intake can influence the regulation of energy balance and, in consequence, the control of body weight. Two aspects of this question must be considered: the daily number of eating occasions and their temporal distribution. Since the 1960s, epidemiological studies have reported an inverse relationship between frequency of eating and body weight, suggesting that a "nibbling" pattern could help to prevent obesity. This notion has later been put into question by the recognition of a high level of dietary underreporting in overweight individuals. In addition, no difference in total daily energy expenditure has been documented as a function of daily meal number. Weight loss is not facilitated by high meal frequency. Snacking in obese subjects is associated with higher energy and fat intake. By contrast, in normal-weight people, snacking does not necessarily lead to increased energy intake, while snacks often contain more carbohydrates and less fat than regular meals. Obese people tend to eat little in the morning and much in the afternoon and the evening. In extreme cases, a "night-eating syndrome" is observed. Understanding the relationship between the circadian distribution of intake and obesity (or resistance to weight loss) seems critical for theoretical as well as clinical reasons."
Impact of the daily meal pattern on energy balance; Scandinavian Journal of Nutrition, Volume 48, Number 3, October 2004 , pp. 114-118(5)
2. "Several epidemiological studies have observed an inverse relationship between people's habitual frequency of eating and body weight, leading to the suggestion that a 'nibbling' meal pattern may help in the avoidance of obesity. A review of all pertinent studies shows that, although many fail to find any significant relationship, the relationship is consistently inverse in those that do observe a relationship. However, this finding is highly vulnerable to the probable confounding effects of post hoc changes in dietary patterns as a consequence of weight gain and to dietary under-reporting which undoubtedly invalidates some of the studies. We conclude that the epidemiological evidence is at best very weak, and almost certainly represents an artefact. A detailed review of the possible mechanistic explanations for a metabolic advantage of nibbling meal patterns failed to reveal significant benefits in respect of energy expenditure. Although some short-term studies suggest that the thermic effect of feeding is higher when an isoenergetic test load is divided into multiple small meals, other studies refute this, and most are neutral. More importantly, studies using whole-body calorimetry and doubly-labelled water to assess total 24 h energy expenditure find no difference between nibbling and gorging. Finally, with the exception of a single study, there is no evidence that weight loss on hypoenergetic regimens is altered by meal frequency. We conclude that any effects of meal pattern on the regulation of body weight are likely to be mediated through effects on the food intake side of the energy balance equation."
Meal frequency and energy balance. Br J Nutr. 1997 Apr;77 Suppl 1:S57-70.
3. OBJECTIVE: To test if a diet of 4.2 MJ/24 h as six isocaloric meals would result in a lower subsequent energy intake, or greater energy output than (a) 4.2 MJ/24 h as two isocaloric meals or (b) a morning fast followed by free access to food.
CONCLUSIONS: In the short term, meal frequency and a period of fasting have no major impact on energy intake or expenditure but energy expenditure is delayed with a lower meal frequency compared with a higher meal frequency. This might be attributed to the thermogenic effect of food continuing into the night when a later, larger meal is given. A morning fast resulted in a diet which tended to have a lower percentage of energy from carbohydrate than with no fast.
Compared with nibbling, neither gorging nor a morning fast affect short-term energy balance in obese patients in a chamber calorimeter. International Journal Of Obesity, April 2001, Volume 25, Number 4, Pages 519-528
4. "RESULTS: Fasting glucose and insulin values were not affected by meal frequency, but peak insulin and AUC of insulin responses to the test meal were higher after the irregular compared to the regular eating patterns (P < 0.01). The irregular meal frequency was associated with higher fasting total (P < 0.01) and LDL (P < 0.05) cholesterol. CONCLUSION: The irregular meal frequency appears to produce a degree of insulin resistance and higher fasting lipid profiles, which may indicate a deleterious effect on these cardiovascular risk factors."
Regular meal frequency creates more appropriate insulin sensitivity and lipid profiles compared with irregular meal frequency in healthy lean women. Eur J Clin Nutr. 2004 Jul;58(7):1071-7.
5. "During the first 2 days of starvation there is often a small absolute increase in BMR relative to values obtained after an overnight fast."
Protein-Energy Interactions, United Nations University, UN ACC-Subcommittee on Nutrition, the International Dietary Energy Consultancy Group (I/D/E/C/G).
6. "This experiment is the first in humans to show that intermittent fasting increases insulin-mediated glucose uptake rates, and the findings are compatible with the thrifty gene concept."
Effect of intermittent fasting and refeeding on insulin action in healthy men. J Appl Physiol. 2005 Dec;99(6):2128-36. Epub 2005 Jul 28.
7. "Dietary restriction has been shown to have several health benefits including increased insulin sensitivity, stress resistance, reduced morbidity, and increased life span.
"intermittent fasting resulted in beneficial effects that met or exceeded those of caloric restriction including reduced serum glucose and insulin levels and increased resistance of neurons in the brain to excitotoxic stress. Intermittent fasting therefore has beneficial effects on glucose regulation and neuronal resistance to injury in these mice that are independent of caloric intake."
Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake. Proc Natl Acad Sci U S A. 2003 May 13; 100(10): 6216–6220.
8. "We conclude that CR and IF dietary regimens can ameliorate age-related deficits in cognitive function by mechanisms that may or may not be related to Abeta and tau pathologies."
Intermittent fasting and caloric restriction ameliorate age-related behavioral deficits in the triple-transgenic mouse model of Alzheimer's disease.
Neurobiol Dis. 2007 Apr;26(1):212-20. Epub 2007 Jan 13.
9. "Although all cells in the body require energy to survive and function properly, excessive calorie intake over long time periods can compromise cell function and promote disorders such as cardiovascular disease, type-2 diabetes and cancers. Accordingly, dietary restriction (DR; either caloric restriction or intermittent fasting, with maintained vitamin and mineral intake) can extend lifespan and can increase disease resistance. Recent studies have shown that DR can have profound effects on brain function and vulnerability to injury and disease. DR can protect neurons against degeneration in animal models of Alzheimer's, Parkinson's and Huntington's diseases and stroke. Moreover, DR can stimulate the production of new neurons from stem cells (neurogenesis) and can enhance synaptic plasticity, which may increase the ability of the brain to resist aging and restore function following injury. Interestingly, increasing the time interval between meals can have beneficial effects on the brain and overall health of mice that are independent of cumulative calorie intake."
Meal size and frequency affect neuronal plasticity and vulnerability to disease: cellular and molecular mechanisms.
J Neurochem. 2003 Feb;84(3):417-31.
10. "Intermittent fasting (IF; reduced meal frequency) and caloric restriction (CR) extend lifespan and increase resistance to age-related diseases in rodents and monkeys and improve the health of overweight humans. Both IF and CR enhance cardiovascular and brain functions and improve several risk factors for coronary artery disease and stroke including a reduction in blood pressure and increased insulin sensitivity. Cardiovascular stress adaptation is improved and heart rate variability is increased in rodents maintained on an IF or a CR diet. Moreover, rodents maintained on an IF regimen exhibit increased resistance of heart and brain cells to ischemic injury in experimental models of myocardial infarction and stroke. The beneficial effects of IF and CR result from at least two mechanisms--reduced oxidative damage and increased cellular stress resistance. Recent findings suggest that some of the beneficial effects of IF on both the cardiovascular system and the brain are mediated by brain-derived neurotrophic factor signaling in the brain. Interestingly, cellular and molecular effects of IF and CR on the cardiovascular system and the brain are similar to those of regular physical exercise, suggesting shared mechanisms. A better understanding of the cellular and molecular mechanisms by which IF and CR affect the blood vessels and heart and brain cells will likely lead to novel preventative and therapeutic strategies for extending health span."
Beneficial effects of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems.
J Nutr Biochem. 2005 Mar;16(3):129-37.
11. "The vulnerability of the nervous system to advancing age is all too often manifest in neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. In this review article we describe evidence suggesting that two dietary interventions, caloric restriction (CR) and intermittent fasting (IF), can prolong the health-span of the nervous system by impinging upon fundamental metabolic and cellular signaling pathways that regulate life-span. CR and IF affect energy and oxygen radical metabolism, and cellular stress response systems, in ways that protect neurons against genetic and environmental factors to which they would otherwise succumb during aging."
Caloric restriction and intermittent fasting: two potential diets for successful brain aging.
Ageing Res Rev. 2006 Aug;5(3):332-53. Epub 2006 Aug 8.
12. "These results demonstrate that GH—possibly by maintenance of circulating concentrations of free IGF-I—is a decisive component of protein conservation during fasting and provide evidence that the underlying mechanism involves a decrease in muscle protein breakdown."
The Protein-Retaining Effects of Growth Hormone During Fasting Involve Inhibition of Muscle-Protein Breakdown. Diabetes 50:96-104, 2001
13. "Glucose kinetics and organ substrate balance were measured basally and for 5 h after eating pizza (600 kcal) containing carbohydrates 75 g as starch, proteins 37 g, and lipids 17 g.
It is concluded that in human subjects, 1) the absorption of a natural mixed meal is still incomplete at 5 h after ingestion"
Splanchnic and leg substrate exchange after ingestion of a natural mixed meal in humans. Diabetes, Vol 48, Issue 5 958-966, (1999)
14. "When the diet was served in six equal meals per (lay, the women’s mean serum cholesterol level was intermediate between but not significantly different from that observed on the three meals per day or two small and one large meal per day regimens. Serum levels of phospholipids, glycerides, and total fatty acids were not significantlyn affected by the frequency or size of meals. No significant differences among the regimens were observed in the retention of nitrogen, calcium, magnesium, and phosphorus, in fat digestibility, or in urinary excretion of thiamine and riboflavin."
Frequency and size of meals and serum lipids, nitrogen and mineral retention, fat digestibility, and urinary thiamine and riboflavin in young women. Am J Clin Nutr. 1967 Aug;20(8):816-24.
15. "The results suggest that muscle protein synthesis responds rapidly to increased availability of amino acids but is then inhibited, despite continued amino acid availability. These results suggest that the fed state accretion of muscle protein may be limited by a metabolic mechanism whenever the requirement for substrate for protein synthesis is exceeded."
"Furthermore the oversupply of amino acids beyond the currently identified requirement when given continuously may have no benefit in stimulating tissue synthesis but merely stimulate the induction of enzymes of amino acid catabolism"
Latency and duration of stimulation of human muscle protein synthesis during continuous infusion of amino acids. Journal of Physiology (2001), 532.2, pp. 575-579
16. "To determine whether human lipogenesis is influenced by the frequency of meal consumption, 12 subjects were divided into two groups and fed isocaloric nutritionally adequate liquid diets over 3 days, either as three larger diurnal (n = 6) or as six small, evenly spaced (n = 6) meals per day."
"These findings suggest that consuming fewer but larger daily meals is not accompanied by increases in triglyceride fatty acid synthesis, despite the observation of hormonal peaks."
Meal frequency influences circulating hormone levels but not lipogenesis rates in humans. Metabolism. 1995 Feb;44(2):218-23.
17. "A gorging pattern of energy intake resulted in a stronger diurnal periodicity of nutrient utilization, compared to a nibbling pattern. However, there were no consequences for the total 24 h energy expenditure (24 h EE) of the two feeding patterns (5.57 +/- 0.16 kJ/min for the gorging pattern; 5.44 +/- 0.18 kJ/min for the nibbling pattern). Concerning the periodicity of nutrient utilization, protein oxidation during the day did not change between the two feeding patterns. In the gorging pattern, carbohydrate oxidation was significantly elevated during the interval following the first meal (ie from 1200 h to 1500 h, P less than 0.01) and the second meal (ie from 1800 h to 2100 h, P less than 0.05). The decreased rate of carbohydrate oxidation observed during the fasting period (from rising in the morning until the first meal at 1200 h), was compensated by an increased fat oxidation from 0900 to 1200 h to cover energy needs. In the nibbling pattern, carbohydrate and fat oxidation remained relatively constant during the active hours of the day."
Influence of the feeding frequency on nutrient utilization in man: consequences for energy metabolism. Eur J Clin Nutr. 1991 Mar;45(3):161-9.
18. "RESULTS: There were no significant alterations in either the positive or negative regulators of muscle mass at either 15 or 40 h, when compared to gene expression measured 3 h after a meal. Similarly, plasma myostatin and IGF-1 were also unaltered at these times. CONCLUSIONS: Unlike previous observations in catabolic and cachexic diseased states, short-term fasting (40 h) fails to elicit marked alteration of the genes regulating both muscle-specific protein synthesis or atrophy. Greater periods of fasting may be required to initiate coordinated inhibition of myogenic and atrogenic gene expression."
Actions of short-term fasting on human skeletal muscle myogenic and atrogenic gene expression. Ann Nutr Metab. 2006;50(5):476-81. Epub 2006 Aug 24.
19. "Irregular meal frequency led to a lower postprandial energy expenditure compared with the regular meal frequency, while the mean energy intake was not significantly different between the two. The reduced TEF with the irregular meal frequency may lead to weight gain in the long term."
Decreased thermic effect of food after an irregular compared with a regular meal pattern in healthy lean women. Int J Obes Relat Metab Disord. 2004 May;28(5):653-60.
20. "We conclude that increasing MF does not promote greater body weight loss under the conditions described in the present study."
Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8-week equi-energetic energy-restricted diet. Br J Nutr. 2009 Nov 30:1-4.
21. Iwao S, et al. Effects of meal frequency on body composition during weight control in boxers. Scand J Med Sci Sports. 1996 Oct;6(5):265-72.
22. Stote KS, et al. A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults. Am J Clin Nutr. 2007 Apr;85(4):981-8.
23. Cameron JD et al. Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8-week equi-energetic energy-restricted diet. Br J Nutr. 2010 Apr;103(8):1098-101. Epub 2009 Nov 30.