Skip to main content
Log in

Development of Obesity is Associated with Increased Calories per Meal Rather than per Day. A Study of High-Fat Diet-Induced Obesity in Young Rats

  • Animal Research
  • Published:
Obesity Surgery Aims and scope Submit manuscript



We challenge the current belief that obesity is a result of overnutrition by studying a rodent model of human obesity.


Male Sprague-Dawley rats at 3 weeks of age were fed with a mixed normal diet of 10% fat and high-fat diet of 60% fat (50:50) for 2 weeks and then turned to 100% high-fat diet until 43 weeks of age. Body weight gain was recorded, and food intake, eating behavior, and metabolic variables were measured by a comprehensive laboratory animal monitoring system. Body composition was determined by dual-energy X-ray absorptiometry. Ghrelin/obestatin-producing A-like cells in the stomach were analyzed by immunohistochemistry.


Rats on high-fat diet were overweight at 9 weeks of age and later became obese characterized by increased body weight and excess fat deposition. There were no obesity-prone, obesity middle tertile, and obesity-resistant subgroups in rats on high-fat diet. The young rats on high-fat diet, even before becoming overweight (i.e., 8 weeks), consumed larger portion of meal (kilocalorie per meal) and ate faster but less frequent than the rats on normal diet. Obese rats had reduced food intake (expressed as gram per 100-g body weight per 24 h), unchanged calorie intake (kilocalorie per 100-g body weight per 24 h), and energy expenditure (kilocalorie per hour per 100-g body weight), and increased number of A-like cells in the stomach.


Large size of meal, but not overnutrition, appears to be responsible for high-fat diet-induced obesity in rats. We propose a consideration that prevention strategies for obesity epidemic should strongly focus on meal size at early childhood and adolescence.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others


  1. Maximova K, McGrath JJ, Barnett T, et al. Do you see what I see? Weight status misperception and exposure to obesity among children and adolescents. Int J Obes (Lond). 2008;32:1008–15.

    Article  CAS  Google Scholar 

  2. Editorial. Curbing the obesity epidemic. Lancet. 2005;367:1549.

    Google Scholar 

  3. King D. Foresight report on obesity. Lancet. 2007;370:1754.

    Article  Google Scholar 

  4. Michels KB, Willett WC, Graubard BI, et al. A longitudinal study of infant feeding and obesity throughout life course. Int J Obes (Lond). 2007;31:1078–85.

    Article  CAS  Google Scholar 

  5. Rice S, McAllister EJ, Dhurandhar NV. Fast food: friendly? Int J Obes (Lond). 2007;31:884–6.

    Article  CAS  Google Scholar 

  6. Bray GA, Tartaglia LA. Medicinal strategies in the treatment of morbid obesity. Nature. 2000;404:672–7.

    Article  CAS  Google Scholar 

  7. Mun EC, Blackburn GL, Matthews JB. Current status of medical and surgical therapy for obesity. Gastroenterology. 2001;120:669–81.

    Article  CAS  Google Scholar 

  8. Solomon C, Dluhy RG. Bariatric surgery—quick fix or long-term solution? N Engl J Med. 2004;351:2751–3.

    Article  CAS  Google Scholar 

  9. Wolfe BM, Austrheim-Smith IT, Ghaderi N. Surgical treatment of obesity: pyloric electrical stimulation. Gastroenterology. 2005;128:225–8.

    Article  Google Scholar 

  10. O'Brien PE, McPhail T, Chaston TB, et al. Systematic review of medium-term weight loss after bariatric operations. Obes Surg. 2006;16:1032–40.

    Article  Google Scholar 

  11. Stettler N. Nature and strength of epidemiological evidence for origins of childhood and adulthood obesity in the first year of life. Int J Obes (Lond). 2007;31:1035–43.

    Article  CAS  Google Scholar 

  12. Stender S, Dyerberg J, Astrup A. Fast food: unfriendly and unhealthy. Int J Obes (Lond). 2007;31:887–90.

    Article  CAS  Google Scholar 

  13. Speakman J, Hambly C, Mitchell S, et al. Animal models of obesity. Obes Rev. 2007;8(Suppl 1):55–61.

    Article  Google Scholar 

  14. Buettner R, Schölmerich J, Bollheimer LC. High-fat diets: modeling the metabolic disorders of human obesity in rodents. Obesity (Silver Spring). 2007;15:798–808.

    Article  CAS  Google Scholar 

  15. Stenström B, Furnes MW, Tømmerås K, et al. Mechanism of gastric bypass-induced body weight loss: one-year follow-up after micro-gastric bypass in rats. J Gastrointest Surg. 2006;10:1384–91.

    Article  Google Scholar 

  16. Furnes MW, Tømmerås K, Arum CJ, et al. Gastric bypass surgery causes body weight loss without reducing food intake in rats. Obes Surg. 2008;18:415–22.

    Article  Google Scholar 

  17. Furnes MW, Stenström B, Tømmerås K, et al. Feeding behavior in rats subjected to gastrectomy or gastric bypass surgery. Eur Surg Res. 2008;40:279–88.

    Article  CAS  Google Scholar 

  18. Varma M, Chai JK, Meguid MM, et al. Effect of estradiol and progesterone on daily rhythm in food intake and feeding patterns in Fischer rats. Physiol Behav. 1999;68:99–107.

    Article  CAS  Google Scholar 

  19. Levin BE, Triscari J, Hogan S, et al. Resistance to diet-induced obesity: food intake, pancreatic sympathetic tone, and insulin. Am J Physiol. 1987;252:R471–8.

    CAS  PubMed  Google Scholar 

  20. Levin BE, Richard D, Michel C, et al. Differential stress responsivity in diet-induced obese and resistant rats. Am J Physiol Regul Integr Comp Physiol. 2000;279:R1357–64.

    Article  CAS  Google Scholar 

  21. Chang S, Graham B, Yakubu F, et al. Metabolic differences between obesity-prone and obesity-resistant rats. Am J Physiol. 1990;259:R1103–10.

    CAS  PubMed  Google Scholar 

  22. Pagliassotti MJ, Knobel SM, Shahrokhi KA, et al. Time course of adaptation to a high-fat diet in obesity-resistant and obesity-prone rats. Am J Physiol. 1994;267:R659–64.

    Article  CAS  Google Scholar 

  23. Zorrilla EP, Inoue K, Fekete EM, et al. Measuring meals: structure of prandial food and water intake of rats. Am J Physiol Regul Integr Comp Physiol. 2005;288:R1450–67.

    Article  CAS  Google Scholar 

  24. Zhao CM, Furnes MW, Stenström B, et al. Characterization of obestatin- and ghrelin-producing cells in the gastrointestinal tract and pancreas of rats: an immunohistochemical and electron-microscopic study. Cell Tissue Res. 2008;331:575–87.

    Article  CAS  Google Scholar 

  25. Archer ZA, Rayner DV, Rozman J, et al. Normal distribution of body weight gain in male Sprague-Dawley rats fed a high-energy diet. Obes Res. 2003;11:1376–83.

    Article  CAS  Google Scholar 

  26. Archer ZA, Corneloup J, Rayner DV, et al. Solid and liquid obesogenic diets induce obesity and counter-regulatory changes in hypothalamic gene expression in juvenile Sprague-Dawley rats. J Nutr. 2007;137:1483–90.

    Article  CAS  Google Scholar 

  27. Elder KA, Wolfe BM. Bariatric surgery: a review of procedures and outcomes. Gastroenterology. 2007;132:2253–71.

    Article  Google Scholar 

  28. Editorial: Time to supersize control efforts of obesity. Lancet. 2007; 370:1521

  29. Cohen D, Farley TA. Eating as an automatic behavior. Prev Chronic Dis. 2008;5:1–7.

    Google Scholar 

  30. Berg C, Lappas G, Wolk A, et al. Eating patterns and portion size associated with obesity in a Swedish population. Appetite. 2009;52:21–6.

    Article  Google Scholar 

Download references


We thank Karin Tømmerås (Ph.D.) and Carl-Jørgen Arum (MD) for valuable discussions, Endre Andersen (Ph.D.) for statistical advice, and Trine Skoglund for technical assistance in measuring the serum ghrelin and obestatin concentrations at the Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology. We also thank Morten Grønli and Erik Langørgen at the Department of Energy and Process Engineering for providing bomb calorimeter. This study was supported by grants from the Research Council of Norway and St. Olavs’ Hospital Foundation for Cancer Research. Marianne W. Furnes received a short-term Ph.D. stipend from the Department of Cancer Research and Molecular Medicine.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Duan Chen.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Furnes, M.W., Zhao, CM. & Chen, D. Development of Obesity is Associated with Increased Calories per Meal Rather than per Day. A Study of High-Fat Diet-Induced Obesity in Young Rats. OBES SURG 19, 1430–1438 (2009).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: