I have just began my experiment for just one week. I plan to induce disorder of lipid metabolism in mice. This is my diet supply: high fat diet(60% calories from fat, D12492, Research Diet), control diet(10% calories from fat, D12450B, Research Diet). Body weight and food intake were recorded every 3 or 4 day. Food intake was normalized by body weight, as graph suggest, mice in high fat diet group(HFD) uptake less than control group(body weight haven't seen significant decrease.). It seems that mice doesn't like HFD, so I am worried about wether this would lead to experiment fail. Could you please give me some suggestion? What I can do now? Continue to observe without any intervention? Or take measures to help mice uptake HFD?
Hi Miao Xu ,
since you just switched to a new diet, it is quite normal that mice have to adapt to it. In my experience, however, in the first 2 weeks with HFD, mice greatly increase their body weight, compared with control chow fed group (2 or more grams per week). By the way, you don't need to check weight every 3-4 days, just do it once a week.
Then I noticed that HFD group eat less grams than control group, but if you also must consider that the amount of calories per gram of food is much different between the two diets. Moreover, I measured body composition with an EchoMRI system, and I clearly saw an increase in fat mass.
If you don't see any increase in body weight after a couple of weeks, however, it might mean that the diet is not working.
There can be different reasons for that.
First of all: which mouse strain are you using? Not all strains are suitable, as some are HFD-resistant. C57BL/6 (or black 6 mice) are good, balb/c are not.
When are you starting the HFD regime? If started too early (mice younger than 8-10 wks), mice microbiome is not "mature", and HFD won't work so well.
Where do you store the HFD food, and how frequently are you changing it? If you keep the food at RT, and if you leave it in the cages for too many days, the food will probably become rancid, and therefore less palatable for mice. I usually keep the food at 4°C, and put some pellets in each cage, checking it every 2-3 days.
I hope this can help you!
As Stefano Ciciliot mentioned. I wanted to attract your attention to the number of calories. Yes they eating less but perhaps the amount of calories is more. Good luck Miao Xu
Give them time. In my case i have seen a significant weight difference in 14 days using Sprague dawley rats and was measuring it once a week. As mentioned by Stefano Ciciliot and Hussain Alsaffar the little amount they eat contains much more calories than normal chow eat by the control.
Much appreciation to your suggestions! It helps me a lot!
This week animals' body weight has increased, they do eat less food compared with control, but total calories intake is higher. Does the pellets help a lot? I didn't prepare it for them, I will try your suggestion. Thanks again!@Stefano Ciciliot
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