If your horse is being fed good-quality forage and a well-formulated concentrate and he’s staying in moderate body condition, then he is probably not a candidate for a low-starch concentrate.

Low-starch concentrates were created by nutritionists to help horses diagnosed with metabolic conditions such as tying-up (recurrent exertional rhabdomyolysis and polysaccharide storage myopathy), Cushing’s disease, and equine metabolic syndrome. Scientific investigation revealed that horses with these conditions benefited from a reduction in starch intake. However, these horses represent only a small portion of the horse population. Because low-starch products are rather commonplace now and because they are unquestionably useful for certain horses, more and more horsemen believe their horses should be consuming them, even when there is no medical or nutritional basis.

Owners of overweight horses sometimes believe that a low-starch concentrate is appropriate, even necessary, for their charges. Just because a horse is obese does not mean that it is insulin resistant. Over time obesity might lead to insulin insensitivity, thereby setting the stage for health problems, but obesity without an accompanying metabolic condition can usually be managed without using a low-starch concentrate.

Successful management of obesity involves two key elements, a decrease in calorie consumption and an increase in exercise. Reducing calorie intake will typically involve feeding quality grass hay (not alfalfa, as it’s too calorie-dense) and a concentrated supplement that will supply the horse with the nutrients it needs for optimal health.

Exercise can take many forms, but there is no question it is an important part of the weightloss equation. Some researchers feel exercise might be the most critical component in sidestepping insulin resistance. This belief was recently supported when Kentucky Equine Research (KER) assessed a group of nearly 200 sport horses (hunters, jumpers, dressage horses), many of which where overweight.

Only about 10% of horses with a body condition score of 7 or greater (considered fleshy with noticeable deposition of fat) were found to be hyperinsulinemic (high levels of insulin in the blood). This differs considerably from a previous study in which 43% of horses with a body condition score of 7 or greater were found to be hyperinsulinemic.

The earlier study involved horses with inactive lifestyles. The horses in the KER study were subjected to near-daily physical conditioning. Therefore, it seems as though overweight horses in regular training are less likely to be hyperinsulinemic than sedentary obese horses.

While it might be tempting to jump on the low-starch bandwagon, be certain it is appropriate for your horse. Consultation with an equine nutritionist is the best way to ensure your horse is on an appropriate diet.