Diets with 55-60% of calories from fat like?TD.06414?and?TD.93075?are commonly used for inducing obesity in rodents. While considered extreme compared to typical human fat consumption, these diets are effective in initiating rapid weight gain in most rodents. With higher fat content there is less room for carbohydrate, thus the carbohydrate (particularly sucrose) amount is relatively low compared to other obesity inducing diets. If you are interested in high fat and high carbohydrate, look at diets with 40-45% of calories from fat (often referred to as western diets).

As the fat level increases, pellet quality (durability) is often compromised. Some higher fat formulas are available only in non-pelleted form or require specific carbohydrate, maltodextrin, for pelleting. Depending on the fat and carbohydrate sources used, the non-pelleted form could be dense and crumbly, dough-like, or paste-like. Though a little more challenging to work with, non-pelleted diet is still used by many researchers for diet-induced obesity models as these researchers suspect the softer form may enhance obesity development.

Diets with 40-45% of calories from fat, like?TD.95217,?TD.88137,?TD.06415, and?TD.08811, represent another popular diet pattern for diet-induced obesity work. These diets have double or triple the amount of sucrose found in higher fat diets. High levels of simple carbohydrate like sucrose and fructose may help to promote hypertriglyceridemia, insulin resistance, and fatty liver. Diets with a pattern of high sucrose and high saturated or trans fat are often referred to as “Western Diets” in obesity and cardiovascular fields. Some “Western Diets” have further modifications to the fatty acid profile or even specific vitamin and minerals adjustments to be even more closely matched to a Western Diet pattern. For specific fatty acid modifications, see examples on our?fat/lipid adjusted diets?page.

Many of the same diets used for inducing obesity in rodents can be used to enhance diabetes related phenotypes like insulin resistance and glucose intolerance. However, fasting hyperglycemia characteristic of diabetes (glucose > 200 mg/dL) is uncommon with a diet only approach. Pre-feeding a high fat diet to induce a certain level of obesity and insulin resistance and then giving low-dose streptozotocin (STZ) may be an effective approach if overt hyperglycemia is desired.

There are many options with different levels and types of fat in addition to different types of carbohydrate ranging from sucrose (highly refined, simple digestion) to corn starch (refined, but more complex) to resistant starch (refined, but not fully digestible). A very basic purified control diet would be AIN-93M (TD.94048) or AIN-93G (TD.94045). AIN-93 diets have a moderate amount of sucrose at ~10%, and fat is from soybean oil with a healthy fatty acid profile. Additional examples of controls for specific DIO diets can be found in the above tables.

Many researchers choose to compare their high fat fed animals to animals fed a natural ingredient, grain-based diet (also referred to as standard diets or chow). These diets differ in the source and level of nutrients as well as in the presence of non-nutritive factors (such as phytates or phytoestrogens). Depending on what your main comparisons are, it may be suitable to have a grain-based diet as your control/reference group. However, making such comparisons limits inferences to dietary patterns versus a specific dietary component.