Fat is not a bad thing. It acts as an energy store, insulates the body and helps regulate insulin. Problems occur when there is an excess. Obesity, for horses as for humans, is a negative condition. Although there may be underlying causes, the most common cause of “fat” is a simple equation; energy intake is greater than energy expenditure.
All nutrients carry an energy value. If intake exceeds output, the excess energy is stored as fat; starch, sugars and fat are the most likely culprits, but both protein and fibre have the potential to be converted biochemically into fat.
But why is fat so bad? After all it is a perfectly natural product and an essential nutrient. The answer is quite simple. Fat stores secrete a range of hormone-like chemicals called adipokines. Some, such as leptins, are involved in appetite control whilst others can promote inflammatory markers. Chronic, low level inflammation has many consequences including impacting on muscle and vascular system integrity, immune function and oxidative systems. At the same time, as adipokines have cortisol-like activity, high fat reserves can induce insulin resistance. IR and associated hyperglycemia can lead to muscle degeneration and fatigue. Although this sounds extreme, even minor shifts can reduce physiological efficiency.
In contrast, a horse with a good condition score, and regularly exercised has many advantages. Exercise improves the circulation, maintains muscle stasis and improves glucose uptake into the muscle and cells. This in turn reduces insulin resistance, improving sensitivity and reducing the risk of hypoxia and cellular damage.
However, feeding also has an important role. Reducing starch, sugar and fat reduces the rate of fat deposition. Replacing it with fibre lowers the potential for fat deposition, even when fibre sources have high energy levels; biochemically, the end product of fibre fermentation – the volatile fatty acids – can generate some components of fat – fatty acids – but this is far less energy efficient than conversion of sugar to fat or, indeed, direct absorption of dietary fat.
So a high fibre, low sugar/starch diet, achieved by using a super fibre, such as a beet product, coupled with regular exercise can produce a horse in good condition and help avoid a number of metabolic/physiological problems.