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Visa fullständig version : Kronobiologiska aspekter på födointag och metabolism vad gäller viktpåverkan


King Grub
2010-02-04, 10:12
Summary Overweight and obesity are the result of a chronic positive energy balance, and therefore the only effective therapies are a diet which, on the long term, provides lower calories than the daily expended energy and exercise. Because nearly every physiological and biochemical function of the body shows circadian variations it can be suggested that also different chronobiological aspects of food intake, like time of day, meal frequency and regularity, and also circadian desynchronizations like in shift work may affect energy metabolism and weight regulation. The aim of this review is therefore to summarize and discuss studies that have addressed these issues in the past and to also provide an overview about circadian variations of selected aspects of metabolism, gut physiology and also factors that may influence overall energy regulation. The results show that a chronic desynchronization of the circadian system like in shift work and also sleep deprivation can favour the development of obesity. Also, regarding energy balance, a higher meal frequency and regular eating pattern seem to be more advantageous than taking the meals irregularly and seldom. Additional studies are required to conclude whether time of day-dependent food intake significantly influences weight regulation in humans.

Obes Rev. 2010 Jan 27. Chronobiological aspects of food intake and metabolism and their relevance on energy balance and weight regulation.

dt06mj2
2010-02-04, 11:52
Jag gissar att jag är en idiot men:
Finns det så många (icke-epidemiologiska?) studier där ökad måltidsfrekvens pekar på mindre sannolikhet för övervikt?

Englund
2010-02-05, 07:44
Also, regarding energy balance, a higher meal frequency and regular eating pattern seem to be more advantageous than taking the meals irregularly and seldom
Hur kan de göra ett sådant antagande då det finns flera kontrollerade studier som pekar på att så inte är fallet?
Visst, nästan alla kvasiexperimentella studier pekar åt andra hållet, men de tar ju inte hänsyn till framförallt en megastor confounder, nämligen energiintaget.

Eddie Vedder
2010-02-05, 09:25
Hur kan de göra ett sådant antagande då det finns flera kontrollerade studier som pekar på att så inte är fallet?
Visst, nästan alla kvasiexperimentella studier pekar åt andra hållet, men de tar ju inte hänsyn till framförallt en megastor confounder, nämligen energiintaget.

Nej fast de påstår ju inte att det ger en magiskt ökad eneriförbrukning eller så heller. Utan att man i studier helt enkelt ofta kunnat påveisa hur regelbundet ätande och en mer strukturerad måltidfördelning över dagen "funkar" för många.

Ingen skriver ju något om att det säger emot energibalansen. Den delen av reviewartikeln som behandlar just måltidsfrekvensen är följande:

In Western societies it is usual to consume three main meals per day, i.e. breakfast, lunch and dinner. However there are major differences in the importance of the meals between different countries. Whereas breakfast is very important in Great Britain and Germany it is reduced to Coffee and Croissant or Cornetto in France and Italy, respectively. Also dinner times can markedly vary between the countries. In Germany and Austria dinner is typically between 18.00 and 20.00 h whereas in the Mediterranean regions it usually begins after 20.00 h(78). In addition to three main meals, people in several countries do also take snacks between the meals. Beside geographically differences one should also consider religious aspects, especially the Ramadan in Muslim cultures, which is discussed following.

The first description of the relationship between meal frequency and energy balance was in the 1960s from Fabry et al.(79). In their study in Czechoslovakian elderly men an inverse relationship between body weight and meal frequency was described. About half of the subsequent studies confirmed these results as reviewed by Bellisle et al.(80) whereas others did not detected a significant relationship (81). A review from 1997 by Chiva (78) came to the conclusion that meal frequency has not a significant influence on the rate of weight loss during energy restriction and also not on 24-h energy expenditure.

The results from meal frequency studies can be disturbed by the fact that overweight and obese people often underreport their energy intakes by especially do not counting snacks into the meals eaten (82). Also the effect of reverse causality may have an impact on the data (83). That means that people who are overweight may omit meals in order to lose weight.

Chapelot et al. showed that omitting a meal for 4 weeks in people who usually eat four meals per day was followed by increases in fat mass (84). A gorging eating pattern may lead to a modulation of storage and mobilization of nutrients potentially favouring lipogenesis and increase in body weight. On the other hand, eaten more often may potentially prevent metabolic fluctuations. Another study in 14 healthy, normal weight women showed that a decreased inter-meal interval (3 vs. 2 meals over the day) is associated with a better satiety during the day and sustains fat oxidation particularly over the night. However, the different meal pattern had no effect on 24-h energy expenditure or diet-induced thermogenesis (DIT) (85).

In a further study with a randomized crossover design subjects consumed all of their daily calories in either three meals or in one meal. The three-meal diet consisted of a classical 'triad', e.g. breakfast, lunch, dinner whereas the one-meal diet was eaten within a 4-h period in the early evening (86). Various metabolic and physiological parameters were measured. The results showed that the weight and the body fat mass after the one-meal diet was significantly lowered. Furthermore total cholesterol and low-density lipoprotein (LDL) but also HDL were higher in the controlled diet.

An interesting study challenging in part the one breakfast/only three meals per day hypothesis was performed by Speechly and Buffenstein (87). These investigators showed that an isocaloric preload spread over the course of the morning as opposed to a single breakfast leads to a significant lesser energy intake (about 26%) at a subsequent ad libitum lunch. The satiety/hunger measures remained nearly unchanged, around the neutral line, during the isocaloric more frequent meal intake. On the contrary they rose constantly from values indicating satiety to a state of hunger until lunch after the single breakfast. Therefore it was not surprising that study participants ate more during the ad libitum lunch. However despite of this expected finding, this study showed that splitting his breakfast over the morning may help to better control appetite sensations and could show advantageous effects in weight loss regimens.

The effect of pre-meal loads on subsequent in energy intake is not only dependent on meal frequency but also on macronutrient composition. Individuals for example consumed more food after a carbohydrate-rich preload compared with a protein-rich preload (88). High and fast glucose absorption from breakfast meals with a high glycaemic index also can lead to a reactive hypoglycaemia inducing higher appetite and energy intake in the subsequent meal. This could be prevented by spreading the energy on several small meals.

In this context, several studies showed that after larger meals, e.g. gorging, greater fluctuations of metabolites and hormones occur than after smaller, more frequent meals (89–91). For example increasing the number of meals per day can flatten fluctuations in insulin concentrations and also plasma glucose (92). Because a considerable drop in plasma glucose can induce hunger, a more frequent eating can prevent this. It may also be thinkable that more frequent eating can induce more stable and constant plasma levels of intestinal satiety hormones, such as glucagon-like peptide-1, cholecystokinin and peptide YY. In addition to potential positive effects on energy balance, an increased meal frequency is also associated with lower fasting total cholesterol and LDL levels (89,93).


Studierna som det refereras till:

78. Chiva M. Cultural aspects of meals and meal frequency. Br J Nutr 1997; 77(Suppl. 1): S21–S28.
79. Fabry P, Hejl Z, Fodor J, Braun T, Zvolankova K. The frequency of meals. Its relation to overweight, hypercholesterolaemia, and decreased glucose-tolerance. Lancet 1964; 2: 614–615.
80. Bellisle F, McDevitt R, Prentice AM. Meal frequency and energy balance. Br J Nutr 1997; 77(Suppl. 1): S57–S70.
81. Verboeket-van de Venne WP, Westerterp KR, Kester AD. Effect of the pattern of food intake on human energy metabolism. Br J Nutr 1993; 70: 103–115.
82. Heitmann BL, Lissner L. Dietary underreporting by obese individuals – is it specific or non-specific? BMJ 1995; 311: 986–989.
83. Summerbell CD, Moody RC, Shanks J, Stock MJ, Geissler C. Relationship between feeding pattern and body mass index in 220 free-living people in four age groups. Eur J Clin Nutr 1996; 50: 513–519.
84. Chapelot D, Marmonier C, Aubert R, Allegre C, Gausseres N, Fantino M, Louis-Sylvestre J. Consequence of omitting or adding a meal in man on body composition, food intake, and metabolism. Obesity (Silver Spring) 2006; 14: 215–227.
85. Smeets AJ, Westerterp-Plantenga MS. Acute effects on metabolism and appetite profile of one meal difference in the lower range of meal frequency. Br J Nutr 2008; 99: 1316–1321.
86. Stote KS, Baer DJ, Spears K, Paul DR, Harris GK, Rumpler WV, Strycula P, Najjar SS, Ferrucci L, Ingram DK, Longo DL, Mattson MP. A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults. Am J Clin Nutr 2007; 85: 981–988.
87. Speechly DP, Buffenstein R. Greater appetite control associated with an increased frequency of eating in lean males. Appetite 1999; 33: 285–297.
88. Porrini M, Crovetti R, Testolin G, Silva S. Evaluation of satiety sensations and food intake after different preloads. Appetite 1995; 25: 17–30.
89. Jenkins DJ, Wolever TM, Vuksan V, Brighenti F, Cunnane SC, Rao AV, Jenkins AL, Buckley G, Patten R, Singer W, Corey P, Josse RG. Nibbling versus gorging: metabolic advantages of increased meal frequency. N Engl J Med 1989; 321: 929–934.
90. Jenkins DJ, Ocana A, Jenkins AL, Wolever TM, Vuksan V, Katzman L, Hollands M, Greenberg G, Corey P, Patten R, Wong G, Josse RG. Metabolic advantages of spreading the nutrient load: effects of increased meal frequency in non-insulin-dependent diabetes. Am J Clin Nutr 1992; 55: 461–467.
91. Wolever TM. Metabolic effects of continuous feeding. Metabolism 1990; 39: 947–951.
92. Jenkins DJ. Carbohydrate tolerance and food frequency. Br J Nutr 1997; 77(Suppl. 1): S71–S81.
93. Arnold LM, Ball MJ, Duncan AW, Mann J. Effect of isoenergetic intake of three or nine meals on plasma lipoproteins and glucose metabolism. Am J Clin Nutr 1993; 57: 446–451.