two different doses (see Note 11). Conduct the treatments and
prepare carotenoid emulsions as indicated in step 5 of Subheading 3.1.
4. Continue the nutritional and treatment challenge for 5 weeks.
5. Regularly monitor body weight and food intake (twice per
week). The last week of the experiment, it is advisable to
perform analysis and tests in live animals as listed in step 8 of
Subheading 3.1.
6. On day 35 (week 5 of treatment), proceed to the euthanization
and tissue collection, as in steps 9–12 of Subheading 3.1.
4 Notes
1. Several types of high-fat diets can be used to induce obesity.
Cafeteria diet (CAF)-fed rodents represent a useful model to
study human obesity because the CAF is a homemade, palatable, hypercaloric, high-sucrose, and hyperlipidic diet that
induces voluntary hyperphagia resulting in increased body
weight, abdominal fat, hyperinsulinemia, and hyperglycemia,
leading to the metabolic syndrome [27–29]. However, CAF
does not seem to be appropriate to study the biological properties of individual food components such as dietary carotenoids,
since it is an undefined diet whose ingredients can contain
multiple nutrients and nonnutrients compounds. The same
can be said about chow diets, which are undefined diets made
out of raw components (e.g., ground wheat, corn, or oats,
soybean, fish, and vegetable oil, among others). Increasing
the amount of certain macronutrients, such as fats, sucrose or
both, of a defined diet (made up of refined ingredients, such as
cornstarch, sucrose, casein, to name some) is more advisable for
our purpose. Defined diets high in both fat and sucrose produce more deleterious effects on animals than diets high in
either fat or sucrose alone [30], and, moreover, such high-fat
high-sucrose diets more closely mimic most typical human
obesogenic diets [30, 31]. Defined obesogenic diets for
rodents can be either homemade or obtained commercially.
The dietary fat source, as well as the percentage of fat
supplementation, may result in differences in phenotypes.
More pronounced obesity and signs of insulin resistance are
observed when the fat source is rich in saturated fat (such as
lard) or when supplementation rises to 60% of the caloric intake
as fat [32, 33]. Mild obesity challenges (e.g., 40–45% caloric
intake as fat instead of 60%) may be better suited to reveal
moderate effects of food bioactives on obesity development.
Mouse Models to Study Antiobesogenic Effects of Carotenoids
411
prepare carotenoid emulsions as indicated in step 5 of Subheading 3.1.
4. Continue the nutritional and treatment challenge for 5 weeks.
5. Regularly monitor body weight and food intake (twice per
week). The last week of the experiment, it is advisable to
perform analysis and tests in live animals as listed in step 8 of
Subheading 3.1.
6. On day 35 (week 5 of treatment), proceed to the euthanization
and tissue collection, as in steps 9–12 of Subheading 3.1.
4 Notes
1. Several types of high-fat diets can be used to induce obesity.
Cafeteria diet (CAF)-fed rodents represent a useful model to
study human obesity because the CAF is a homemade, palatable, hypercaloric, high-sucrose, and hyperlipidic diet that
induces voluntary hyperphagia resulting in increased body
weight, abdominal fat, hyperinsulinemia, and hyperglycemia,
leading to the metabolic syndrome [27–29]. However, CAF
does not seem to be appropriate to study the biological properties of individual food components such as dietary carotenoids,
since it is an undefined diet whose ingredients can contain
multiple nutrients and nonnutrients compounds. The same
can be said about chow diets, which are undefined diets made
out of raw components (e.g., ground wheat, corn, or oats,
soybean, fish, and vegetable oil, among others). Increasing
the amount of certain macronutrients, such as fats, sucrose or
both, of a defined diet (made up of refined ingredients, such as
cornstarch, sucrose, casein, to name some) is more advisable for
our purpose. Defined diets high in both fat and sucrose produce more deleterious effects on animals than diets high in
either fat or sucrose alone [30], and, moreover, such high-fat
high-sucrose diets more closely mimic most typical human
obesogenic diets [30, 31]. Defined obesogenic diets for
rodents can be either homemade or obtained commercially.
The dietary fat source, as well as the percentage of fat
supplementation, may result in differences in phenotypes.
More pronounced obesity and signs of insulin resistance are
observed when the fat source is rich in saturated fat (such as
lard) or when supplementation rises to 60% of the caloric intake
as fat [32, 33]. Mild obesity challenges (e.g., 40–45% caloric
intake as fat instead of 60%) may be better suited to reveal
moderate effects of food bioactives on obesity development.
Mouse Models to Study Antiobesogenic Effects of Carotenoids
411