Cognitive Behavior
FUTURE DIRECTIONS
One important question which has not been extensively addressed is whether the association between obesity and decrements in cognitive performance is perma-nent. More specifically, can weight loss or other strategies, such as physical activity, reverse the deficits in cognitive behavior observed in obese individuals? Although the answer to this question is important for individuals of all ages, it is particularly important for children and adolescents. Early life is a critical time for learning, and early deficits in learning could translate into lifelong problems that could ultimately impact career advancement, social interactions, and quality of life.
With respect to the preceding question, there is substantial evidence that physi-cal activity is beneficial not only for maintaining physiphysi-cal health but also for pre-serving mental performance. Results of studies in both experimental animals and humans indicate that physical activity can protect against age-related declines in learning and memory. Moreover, there is now evidence that physical activity can increase hippocampal volume and improve memory (Erickson et al. 2011). Emerging work also indicates that physical activity could reverse the harmful effects of obe-sity on brain functioning and behavior. In experimental animals, voluntary wheel running reversed the detrimental effects of a high-fat diet on spatial learning and
hippocampal levels on brain-derived neurotrophic factor (Molteni et al. 2004). In humans, physical activity recently has been found to attenuate the negative relation-ship between central adiposity and cognitive function in healthy community-dwell-ing adults (Dore et al. 2008).
It is important to remember that decrements in cognitive behavior are not univer-sally seen in obese individuals. It is most probable that it is not obesity but rather its metabolic consequences which are responsible for obesity-related alterations in brain functioning. As yet, no studies have compared cognitive functioning in metaboli-cally healthy obese individuals and metabolimetaboli-cally unhealthy individuals. However, this type of research is critical for helping to determine the factors mediating differ-ences in cognitive behavior between lean and obese individuals.
Finally, while certainly important, research on obesity, brain function, and cogni-tion could perpetuate the ongoing negative stereotypes of obesity. It is possible that this negative stereotype contributes, at least in part, to the cognitive deficits observed in some obese individuals. These stereotypes can lead to isolation, depression, and low self-esteem and can create a burden for individuals from the stereotyped groups which can undermine their performance on cognitive tasks (Schmadar et al. 2008). It is thus important for future studies to find ways to integrate the biological and social factors as potential mediators of the effects of obesity on behavior.
REFERENCES
Abbatecola, A. M., F. Lattanzio, L. Spazzafumo, A. M. Molinari, M. Cioffi, R. Canonico, L. DiCiocclo, and G. Paolisso. 2010. Adiposity predicts cognitive decline in older persons with diabetes: a 2 year follow-up. Plos ONE 5: e10333, doi: 10.137/journal.pone.0010333.
Anan, F., R. Masaki, T. Shimomua, M. Fujiki, Y. Umeno N. Eshima, T. Saikawa, and H. Yoshimatus. 2010. Abdominal visceral fat accumulation is associated with hippo-campus volume in non-dementia patients with type 2 diabetes mellitus. Neuroimage 49:57–62.
Arens, R., and H. Muzumdar. 2010. Childhood obesity and obstructive sleep apnea syndrome.
J Appl Physiol 108:436–44.
Beydoun, M. A., H. A. Beydoun, and Y. Wang, Y. 2008. Obesity and central obesity as risk factors for incident dementia and its subtypes: a systematic review and meta-analysis.
Obes Rev 9:204–18.
Bissels, G-J., B. Bravenboer, and G. H. Willem. 2004. Glucose, insulin, and the brain: mod-ulation of cognition and synaptic plasticity in health and disease: A preface. Eur J Pharmacol 490:1–4.
Boeka, A. G., and K. L. Lokken. 2008. Neuropsychological performance of a clinical sample of extremely obese individuals. Arch Clin Neuropsych 23:467–74.
Botero, D., and J. I. Wolfsdorf. 2005. Diabetes mellitus in children and adolescents. Arch Med Res 36:281–90.
Braak, H., and E. Braak. 1991. Demonstration of amyloid deposits and neurofibrillary changes in whole brain sections. Brain Pathol. 1:213–6.
Brogna, A., D. Hevey, G. O. O’Callaghan, R. Yoder, and D. O’Shea. 2011. Impaired decision making among morbidly obese adults. J Psychosom Res 70:189–96.
Buettner, R., J. Scholmerich, and L. C. Bolleimer. 2007. High-fat diets: modeling the meta-bolic disorders of human obesity in rodents. Obesity 15:798–808.
Canning, H., and J. Mayer. 1966. Obesity: its possible effect on college acceptance. New Engl J Med 20:352–4.
Centers for Disease Control and Prevention, Division of Nutrition, Physical Activity and Obesity, National Center for Chronic Disease Prevention and Health Promotion. 2010.
Overweight and obesity: childhood overweight and obesity. www.cdc.gov/nccdphp/dnpao/
Convit, A. 2005. Links between cognitive impairment in insulin resistance: an explanatory model. Neurobiol Aging 26S:S31–5.
Convit, A., O. T. Wolf, C. Tarshish, and M. J. de Leon. 2003. Reduced glucose tolerance is associated with poor memory performance and hippocampal atrophy among normal elderly. Proc Natl Acad Sci USA 100:2019–22.
Cosgrove, R. G., C. Arroyo, J. C. Warren, and J. Zhang. 2009. Impaired cognitive functioning in overweight children and adolescents. Agro Food Industry Hi Tech 20:48–51.
Cournot, M., J. C. Marquie, D. Ansiau, C. Martinaud, H. Fonds, J. Ferrieres, and J. B.
Ruidavets. 2006. Relation between body mass index and cognitive function in healthy middle-aged men and women. Neurology 67:1208–14.
Craft, S. 2009. The role of metabolic disorders in Alzheimer Disease and vascular dementia.
Arch Neurol 66:300–5.
Cserjesi, R., D. Molnar, O. Luminet, and L. Lenard. 2007. Is there a relationship between obesity and mental flexibility in children? Appetite 49:675–8.
Datar, A., R. Sturm, and J. L. Magnabosco. 2004. Childhood overweight and academic perfor-mance: national study of kindergartners and first-graders. Obes Res 12:58–68.
Debette, S., A. Beiser, U. Hoffmann, C. DeCarli, C. J. O’Donnell, J. M. Massaro, R. Au, J. J. Himali, P. A. Wolf, C. S. Fox, and S. Seshadri. 2010. Visceral fat is associated with lower brain volume in healthy middle-aged adults. Ann Neurol 68:136–44.
D’Hooge, R., and P. P. De Deyn. 2001. Applications of the Morris water maze in the study of learning and memory. Brain Res Rev 36:60–90.
Dore, G. A., M. F. Elias, M. A. Robbins, M. M. Budge, and P. K. Elias. 2008. Relation between central adiposity and cognitive function in the Maine-Syracuse Study: attenuation by physical activity. Ann Behav Med 35:341–50.
Duncan, G. E. 2006. Prevalence of diabetes and impaired fasting blood glucose levels among U.S. adolescents: National Health and Nutrition Examination Survey, 1999–2002. Arch Pediatr Adol Med 160:523–8.
Elias, M. F., P. K. Elias, L. M. Sullivan, P. A. Wolf, and R. B. D’Agostino. 2003. Lower cogni-tive function in the presence of obesity and hypertension: The Framingham Heart Study.
Int J Obes 27:260–8.
Elias M. F., P. K. Elias, L. J. Sullivan, P. A. Wolf, and R. B. D’Agostino. 2005. Obesity, diabe-tes and cognitive deficit: the Framingham Heart Study. Neurobiol Aging 26S: S11–S16.
Erickson, K. I., M. W. Voss, R. S. Prakash, C. Basak, A. Szabo, L. Chaddock, J. S. Kim, S. Heo, H. Alves, S. M. White. T. R. Wojcicki, E. Mailey, V. J. Vieira, S. A. Martin, B. D. Pence, J. A. Woods, E. McAuley, and A. F. Kramer. 2011. Exercise training increases size of hippocampus and improves memory. Proc Nat Acad Sci USA 108:3017–22.
Farr, S. A., K. A. Yamada, D. A. Butterfield, H. M. Abdul, L. Xu, N. E. Miller, W. A. Banks, and J. E. Morley. 2008. Obesity and hypertriglyceridemia produce cognitive impair-ment. Endocrinology 149:2628–36.
Finer, N. 2011. Medical consequences of obesity. Medicine 39:18–23.
Flegal, M. M., M. D. Carroll, C. L. Ogden, and L. R. Curtin. 2010. Prevalence and trends in obesity among US adults, 1999–2008. J Amer Med Assoc 303:235–41.
Furukawa, S., T. Fujita, M. Shimabukuro, M. Iwaki, Y. Yamada, and Y. Nakajima. 2004.
Increased oxidative stress in obesity and its impact on metabolic syndrome. J Clin Invest 114:1752–61.
Gazdzinski, S., J. Kornak, M. W. Weiner, D. J. Meyerhoff, and D. R. Nat. 2008. Body mass index and magnetic resonance markers of brain integrity in adults. Ann Neurol 63:652–7.
Gazdzinski, S., R. Millin, L. G. Kaiser, T. C., Durazzo, S. G. Mueller, M. W. Weiner, and D. J.
Meyerhoff. 2010. BMI and neuronal integrity in healthy, cognitively normal elderly: a proton magnetic resonance spectroscopy study. Obesity 18:743–8.
Goldbart, A. D., B. W. Row, L. Kheirandish-Gozal, Y. Cheny, K. R. Brittian, and D. Gozal.
2006. High fat/refined carbohydrate diet enhances the susceptibility to spatial learning deficits in rats exposed to intermittent hypoxia. Brain Res 1090:190–6.
Gonzales, M. M., T. Taurmi, S. C. Miles, Tanaka, H., F. Shah, and A. P. Haley. 2010. Insulin sensitivity as a mediator of the relationship between BMI and working memory-related brain activation. Obesity 18:2131–7.
Gorospe, E. C., and J. K. Dave. 2007. The risk of dementia with increased body mass index.
Age Aging 36:23–9.
Greenwood, C. E., and G. Winocur. 1990. High-fat diets, insulin resistance and declining cog-nitive function. Neurobiol Aging 26S:S42–S45.
Gunstad, J., R. H. Paul, R. A. Cohen, D. F. Tate, M. B. Spitznagel, and E. Gordon. 2007.
Elevated body mass index is associated with executive dysfunction in otherwise healthy adults. Comp Psychiat 48:57–61.
Gustafson, D., E. Rothenberg, K. Blennow, B. Steen, and I. Skoog. 2003. An 18-year follow-up of overweight and risk of Alzheimer disease. Arch Intern Med 163:1524–8.
Gustafson, D., L. Lissner, C. Bengtsson, C. Bjorkelund, and I. Skoog. 2004. A 24-year follow-up of body mass index and cerebral atrophy. Neurology 63:1876–81.
Gustafson, D. R., K. Backman, M. Waern, S. Ostling, X. Guo, P. Zandi, M. M. Mielke, C. Bengtsson, and I. Skoog. 2009. Adiposity indicators and dementia over 32 years in Sweden. Neurology 73:1559–66.
Hassing, L. B., A. K. Dahl, V. Thorvaldsson, S. Berg, M. Gatz, N. L. Pedersen, and B. Johansson. 2009. Overweight in midlife and risk of dementia: a 40-year follow-up study. Int J Obesity 33:893–8.
Hebert, L. E., P. A. Scherr, J. L. Bienias, D. A. Bennett, and D. A. Evans. 2003. Alzheimer’s Disease in the US population. Arch Neurol 60:1119–22.
Hoyer, S. 2003. Memory function and brain glucose metabolism. Pharmacopsychiatry 36:62–7.
Hwang, L., C. Wang, T. Li, S. Chang, L. Lin, C. Chen, C. Chen, K. Liang, I. Ho, W. Yang, and L. Chiou. 2010. Sex differences in high-fat diet-induced obesity, metabolic alterations and learning and synaptic plasticity deficits in mice. Obesity 18:463–9.
Jagust, W., H. Harvey, D. Munga, and M. Haan. 2005. Central obesity and the aging brain.
Arch Neurol 62:1545–8.
Jurdak, N., and R. B. Kanarek. 2009. Sucrose-induced obesity impairs novel object recogni-tion learning in young rats. Physiol Behav 96:1–5.
Jurdak, N., and R. B. Kanarek. 2010. The effects of twelve weeks of sucrose feeding on spa-tial learning and memory and brain-derived neurotrophic factor in young female rats.
Abstract. Society for Neuroscience 509:6.
Jurdak, N., A. Lichtenstein, and R. B. Kanarek. 2008. Diet-induced obesity impairs spatial learning in young male rats. Nutr Neurosci 11:1–6.
Kanarek, R. B., and E. Hirsch. 1977. Dietary-induced overeating in experimental animals. Fed Proc 36:154–8.
Kanoski, S. E., and T. L. Davidson. 2010. Different patterns of memory impairments accom-pany short- and longer-term maintenance on a high-energy diet. J Exp Psychol Anim Behav Process 36:313–9.
Kanoski, S. E., and T. L. Davidson. 2011. Western diet consumption and cognitive impair-ment: links to hippocampal dysfunction and obesity. Physiol Behav 103:59–68.
Kanoski, S. E., R. L. Meisel, A. J. Mullins, and T. L. Davidson. 2007. The effects of energy-rich diets on discrimination reversal learning and on BDNF in the hippocampus and prefrontal cortex of rat. Behav Brain Res 182:57–66.
Kanaya, A. M., K. Lindquist, T. B. Harris, L. Launer, C. Rosano, S. Satterfield, and K. Yaffe. 2009.
Total and regional adiposity and cognitive change in older adults. Arch Neurol 66:329–35.
Karelis, A. D. 2008. Metabolically healthy but obese individuals. Lancet 372:1281–3.
Li Y, Q. Dai, J. C. Jackson, and J. Zhang. 2008. Overweight is associated with decreased cog-nitive functioning among children and adolescents. Obesity 16:1809–15.
Lindqvist, A., P. Mohapel, B. Bouter, H. Frielingsdorf, D. Pizzo, P. Brundin, and C. Erlanson-Albertsson. 2006. High-fat diet impairs hippocampal neurogenesis in male rats. Eur J Neurol 13:1385–8.
Linnarsson, S., A. Bjorklund, and P. Ernfors. 1997. Learning deficit in BDNF mutant mice.
Eur J Neurosci 9:2581–7.
Lokken, K. L., A. G. Boeka, H. M. Austin, J. Gunstad, and C. M. Harmon. 2009. Evidence of executive dysfunction in extremely obese adolescents: A pilot study. Surg Obes Relat Dis, 5:547–52.
Luchsinger, A. J. 2010. Type 2 diabetes and related conditions relation to dementia: an oppor-tunity for prevention? J Alzheimers Dis 20:723–36.
Luchsinger, A. J., and D. R. Gustafson. 2009. Adiposity and Alzheimer’s disease. Curr Opin Clin Nutr Metabol Care 12:15–21.
McNay, E. C., C. T. Ong, R. J. McCrimmon, J. Cresswell, J. S. Bogan, and R. S. Sherwin.
2010. Hippocampal memory processes are modulated by insulin and high-fat-induced insulin resistances. Neurbiol Learn Mem 93:546–53.
Messier, C., M. Tsiakas, M. Gagnon, and A. Desrochers. 2010. Effect of age and glucoregula-tion on cognitive performance. J Clin Exp Neuropsychol 32:809–21.
Mizuno, M., Yamada, K., Olariu, A., Nawa, and H. Nabeshim. 2000. Involvement of brain-derived neurotrophic factors in spatial memory formation and maintenance in a radial arm maze in rats. J Neurosci 20:7116–21.
Molteni, R., R. J. Bernard, Z. Ying, C. K. Roberts, and F. Gomez-Pinilla. 2002. A high fat, refined sugar diet reduces brain-derived neurotrophic factor, neuronal plasticity, and learning. Neurosci 112:803–14.
Molteni, R., A. Wu, S. Vaynman, Z. Ying, R. J. Barnard, and F. GÓmez-Pinilla. 2004. Exercise reverses the harmful effects of consumption of a high-fat diet on synaptic and behav-ioral plasticity associated to the action of brain-derived neurotrophic factor. Neurosci 123:429–40.
Morris, R. 1984. Development of a water-maze procedure for studying spatial learning in the rat. J Neurosci Methods 11:47–60.
Morrison, C. D., P. P. Pistell, D. K. Ingram, W. D. Johnson, Y. Liu, S. O. Feranandez-Kim, C. L. White, M. N. Purpera, R. M. Uranga, A. J. Bruce-Keller, and J. N. Keller. 2010.
High fat diet increases hippocampal oxidative stress and cognitive impairment in aged mice: implications for decreased NrF2 signaling. J. Neurochem. 114:1581–9.
Murray A. J., N. S. Knight, L. E. Cochlin, S. McAleese, R. M. J. Deacon, N. P. Rawlins, and K. Clarke. 2009. Deterioration of physical performance and cognitive function in rats with short-term high-fat feeding. FASEB J 23:4353–60.
Naderali, E. K., S. H. Ratcliffe, and M. C. Dale. 2009. Obesity and Alzheimer’s disease: a link between body weight and cognitive function in old age. Am J Alzheimer’s Dis.
24:445–8.
Pannacciulli, N., A. Del Parigi, K. Chen, D. S. Le, N. T. E. M. Reiman, and P. A. Tataranni.
2006. Brain abnormalities in human obesity: a voxel-based morphometric study.
Neuroimage 31:1419–25.
Park C. R., R. J. Seeley, S. Craft, and S. C. Woods. 2000, Intracerebroventricular insulin enhances memory in a passive-avoidance task. Physiol Behav 68:509–14.
Park H. R., M. Park, J. Choi, K-Y. Park, H. Y. Chung, and J. Lee. 2010. A high-fat diet impairs neurogenesis: involvement of lipid peroxidation and brain-derived neurotrophic factor.
Neurosci. Lett 482:235–9.
Pathan, A., A. Gaikwas, B. Visanad, and P. Romarao. 2008. Rosiglitazone attenuates the cogni-tive deficits induced by high fat feeding in rats. Eur J Pharmacol 589:176–9.
Perry, R. J., and J. R. Hodges. 1999. Attention and executive deficits in Alzheimer’s disease. A critical review. Brain 122:383–404.
Pistell, P. J., C. D. Morrison, S. Gupta, A. G. Knight, J. N. Keller, D. K. Ingram, and A. J.
Bruce-Keller. 2010. Cognitive impairment following high fat diet consumption is asso-ciated with brain inflammation. J Neuroimmunol 219:25–32.
Profenno, L. A., A. P. Porsteinsson, and S. V. Faraone, S. V. 2010. Meta-analysis of Alzheimer’s disease risk with obesity, diabetes and related disorders. Biol Psychiat 67:505–12.
Puhl, R. M., and J. D. Latner. 2007. Stigma, obesity, and the health of the nation’s children.
Psychol Bull 133:557–80.
Raji, C. A., A. J. Ho, N. N. Parikshak, J. T. Becker, O. L. Lopez, L. H. Kuller, X. Hua, A. D. Leow, A. W. Toga, and P. M. Thompson. 2010. Brain structure and obesity. Human Brain Mapping 31:353–64.
Ramaswamy R., M. Mirochna, and L. C. Perlmutter. 2010. The negative association of BMI with classroom effort in elementary school children. J Child Health Care 14:161–9.
Reagan, L. P. 2007. Insulin signaling effects on memory and mood. Curr Opin Pharmacol 7:633–7.
Reijmer, Y., D. E. van den Berg, C. Ruis, L. J. Kappelle, and G. J. Biessels. 2010. Cognitive dysfunction in patients with type 2 diabetes. Diab-Metabol Res Rev. 26:507–19.
Roberts, C. K., B. Freed, and W. J. McCarthy. 2010. Low aerobic fitness and obesity are associated with lower standardized test scores in children. J Pediatr. 156:711–8, 718.e1.
Ross, A. P., T. J., Bartness, J. G. Mielke, and M. B. Parent. 2009. A high fructose diet impairs spatial memory in male rats. Neurobiol Learn Mem 92:410–6.
Ryan C., M. Freed, J. Rood, A. Cobitz, B. Waterhouse, and M. Strachan. 2006. Improving metabolic control leads to better working memory in adults with type 2 diabetes. Diab Care 29:345–51.
Saland, J. M. 2007. Update on the metabolic syndrome in children. Curr Opin Pediatr 19:
183–91.
Schmader, T., M. Johns, and C. Forbes. 2008. An integrated process model of stereotype threat on performance. Psychol Rev 115:336–56.
Shimamura, A. P. 2010. Hierarchical relational binding in the medial temporal lobe: the strong get stronger. Hippocampus 20:1206–16.
Shoelson, S. E., L. Herrero, and A. Naaz. 2007. Obesity, inflammation, and insulin resistance.
Gastroenterology 132:2169–80.
Stefan, N., K. Kantartzis, J. Machann, F. Schick, C. Thamer, K. Rittig, B. Balletshofer, F. Machicao, A. Fritsche, and H-U. Haring. 2008. Indentification and characterization of metabolically benign obesity in humans. Arch Intern Med 168:1609–16.
Stranahan, A. M., E. D. Norman, K. Lee, R. G. Cutler, R. S. Telljohann, J. M. Egan, and M. P. Mattson. 2008. Diet-induced insulin resistance impairs hippocampal synaptic plasticity and cognition in middle-aged rats. Hippocampus 18:1085–8.
Taki, Y., S. Kinomura, K. Sato, K. Inoue, R. Goto, K. Okada, S. Uchida, R. Kawashima, and H.
Fukuda. 2008. Relationship between body mass index and gray matter volume in 1,428 healthy individuals. Obesity 16:119–24.
Uranga, R. M., A. J. Bruce-Keller, C. D. Morrison, S. O. Ferandex-Kim, P. J. Ebenezer, L. Zhang, K. Dasuri, and J. N. Keller, J. N. 2010. Intersection between metabolic dys-function, high fat diet consumption, and brain aging. J Neurochem 114:344–61.
Valladolid-Acebes, I., P. Stucchi, V. Cano, M. S. Fernandez-Alfonso, B. Merino, M. Gil-Ortega, A. Fole, L. Morales, M. Ruiz-Gayo, and N. Del Olmo. 2011. High-fat diets impair spatial learning in the radial-arm maze in mice. Neurobiol Learn Mem 95:
80–5.
Velho, S., F. Paccaud, G. Waeber, P. Vollenweider, and P. Marques-Vidal. 2010. Metabolically healthy obesity: different prevalences using different criteria. Eur J Clin Nutr 64:1043–51.
Verdejo-Garcia, A., M. Perez-Exposito, J. Schmidt-Rio-Valle, M. J. Fernandez-Serrano, and C. Campoy. 2010. Selective alterations within executive functions in adolescents with excess weight. Obesity 18:1572–8.
Volkow, N. D., G. J. Wang, F. Telang, J. S. Fowler, R. Z. Goldstein, N. Alia-Klein, J. Logan, C. Wong, P. K. Thanos, Y. Ma, and K. Pradhan. 2009. Inverse association between BMI and prefrontal metabolic activity in healthy adults. Obesity 12:60–5.
Vorhees, C. V., and M. T. Williams. 2006. Morris water maze: procedures for assessing spatial and related forms of learning and memory. Nat Protoc 1:848–58.
Vos, M. B., and J. Welsh J. 2010. Childhood obesity: update on predisposing factors and pre-vention strategies. Curr Gastroenterol Rep 12:280–7.
Ward, M. A., C. M. Carlsson, M. A. Trivedi, M. A. Sager, and S. C. Johnson. 2005. The effect of body mass index on global brain volume in middle-aged adults: a cross-sectional study. BMC Neurology 5:23 doi:10.1186/1471-2377-5-23.
Walther, K., A. C. Birdsill, E. L. Glisky, and L. Ryan. 2010. Structural brain differences and cognitive functioning related to body mass index in older females. Human Brain Mapping 31:1052–64.
Whitmer, R. A., E. P. Gunderson, E. Barrett-Connor, C. P. Quesenberry, and K. Yaffe, K. 2005.
Obesity in middle age and future risk of dementia: a 27-year longitudinal population based study. BMJ doi:10.1136/bmj.38446.466238.EO.
Whitmer, R. A., D. R. Gustafson, E. Barrett-Connor, N. M. Haan, E. P. Gunderson, and K. Yaffe. 2008. Central obesity and increased risk of dementia more than three decades later. Neurology 71:1057–64.
Wildna, R. P., P. Muntner, K. Reynolds, A. P. McGinn, S. Rajpathak, J. Wylie-Rosett, and M. R. Sowers. 2008. The obese without cardiometabolic risk factor clustering and the normal weight with cardiometabolic risk factor clustering. Arch Intern Med 168:
1617–24.
Winocur, G., and C. E. Greenwood. 1999. The effects of high fat diets and environmental influences on cognitive performance in rats. Behav Brain Res 101:153–9.
Winocur, G., and C. E. Greenwood. 2005. Studies of the effects of high fat diets on cognitive function in a rat model. Neurobiol Aging 26:46–9.
World Health Organization. 2009. Obesity and overweight. World Health Organization. www.
who.int/dietphysicalactivity/publications/facts/en/
World Health Organization. 2011. Obesity and overweight Fact Sheet No. 311. World Health Organization. www.who.int/mediacentre/factsheets/fs311/en/
Wu, A., R. Molteni, Z. Ying, and F. Gomez-Pinilla. 2003. A saturated-fat diet aggravates the outcome of traumatic brain injury on hippocampal plasticity and cognitive function by reducing brain-derived neurotrophic factors. Neuroscience 119:365–75.
Yau, P. L., D. C. Javier, C. M. Ryan, W. H. Tsu, B. A. Ardekani, S. Ten, and A. Convit. 2010.
Preliminary evidence for brain complications in obese adolescents with type 2 diabetes mellitus. Diabetologia 53:2298–306.
Yu, H., X. Bi, W. Ma, L. He, L. Yuan, J. Feng, and R. Xiao. 2010. Long-term effects of high lipid and high energy diet on serum lipid, brain fatty acid composition, and memory and learning ability in mice. Int J Dev Neurosci 28:271–6.
Zhang, L., A. J. Bruce-Keller, K. Dasuri, A. T. Nguyen, Y. Liu, and J. N. Keller. 2009. Diet-induced metabolic disturbances as modulators of brain homeostasis. Biochim Biophys Acta 1792:417–22.
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