Hedonic overdrive mannequin finest explains high-fat diet-induced weight problems in mice

Excessive-fat diets trigger weight problems in male mice. The underlying mechanism, nonetheless, stays controversial. After assessing three contrasting concepts, researchers have decided that the hedonic overdrive mannequin offers one of the best match, based on a brand new research printed within the journal Weight problems, The Weight problems Society’s (TOS) flagship journal.

Our work offers some course as to why high-fat/high-carb macronutrient mixtures stimulate overconsumption. The research is in mice so we must be cautious about extrapolating to people. Nevertheless, if the impact is repeated in people, avoiding the macronutrient combos that stimulate us to overeat would appear an excellent technique to stop weight problems.”

John R. Speakman, director of the Shenzhen Key Laboratory of Metabolic Well being, Heart for Power Metabolism and Copy, Shenzhen Institute of Superior Know-how, Chinese language Academy of Sciences, Shenzhen, China

Speakman is the corresponding creator of the research.

Consultants clarify that when fed a food plan containing greater than 40% fats by energy, the males of many strains of mice deposit massive quantities of physique fats. Nevertheless, the consequences in females are smaller. The underlying mechanism producing the weight problems impact in males is just not nicely understood as a result of research haven’t carried out measurements regularly sufficient or used a ample vary of various diets to check amongst various concepts.

Within the present research, researchers assessed the responses of 240 individually-housed 12-week-old C57BL/6 male mice in opposition to 3 patterns predicted by hedonic overdrive, reverse causality and passive overconsumption fashions. A baseline interval of seven days came about feeding all of the mice a typical low-fat food plan that contained 10% fats, 20% protein and 70% carbohydrate by power. The mice had been then uncovered to 12 completely different diets that different of their fats, protein and carbohydrate contents for 30 days. All of the diets analyzed had greater than 40% fats by energy.

Physique weight and meals consumption had been measured day by day over the baseline interval and after switching to the experimental diets for 30 days. Meals consumption was measured from the burden of meals that went lacking from the meals hopper every day. Mice often pulled pellets of meals via the hopper bars or floor their meals; subsequently, a radical search of the cage was made to return any uneaten meals to the hopper earlier than weighing.

Outcomes confirmed the hedonic overdrive mannequin offered one of the best match for the info evaluation. The reverse causality and passive overconsumption fashions weren’t nicely supported. After publicity to the diets, power consumption elevated first and physique weight adopted later. Consumption then declined. The height power consumption was depending on each dietary protein and carbohydrate, however not the dietary fats and power density, whereas the speed of lower in consumption was solely associated to dietary protein.

On the high-fat diets, the burden of meals consumption declined, however regardless of this common discount of 14.4 g in meals consumption, the mice consumed on common 357 kJ extra power than at baseline. The very fact they gained weight on this state of affairs is a direct refutation of the mass steadiness mannequin of weight problems.

“Utilizing a number of outlined diets various in macronutrient composition adopted by statistical modeling of meals consumption patterns in male mice over a 30-day interval, this research reinforces the concept that food plan palatability, and never power content material, drive overconsumption past precise caloric wants. Because the authors acknowledge, the research additionally reveals that the evaluation of meals consumption patterns requires much more subtle statistical modeling strategies to higher perceive the position of every macronutrient in each the initiation and cessation of consuming,” stated Professor Catherine M. Kotz, PhD, of the College of Minnesota. Kotz was not related to the analysis.

The research’s authors famous that it stays a thriller as to why feminine C57BL/6 mice do not need the identical magnitude of response to overconsumption when uncovered to high-fat diets, and added that this is able to be a worthwhile space for additional analysis.

Different authors of the research embrace Lin Gao, Sumei Hu, Min Li, Xueying Zhang and Chaoqun Niu, Shenzhen Key Laboratory of Metabolic Well being, Heart for Power Metabolism and Copy, Shenzhen Institute of Superior Know-how, Chinese language Academy of Sciences, Shenzhen, China; Dengbao Yang, Lu Wang, Jacques Togo, Yingga Wu, Baoguo Li, Guanlin Wang, Li Li, Yanchao Xu, Moshen Mazidi, State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese language Academy of Sciences, Beijing, China. Gao, Hu, Li, Zhang and Niu are additionally related to this laboratory and institute. Gao additionally works on the College of Chinese language Academy of Sciences, Beijing, China. Authors additionally embrace Elspeth Couper and Andrew Whittington-Davies, Institute of Organic and Environmental Sciences, College of Aberdeen, United Kingdom.