The advice to feed overweight, insulin and leptin resistant horses free choice hay 24/7 just won’t die. Even following the suggested limitations on hay of low sugar and WSC with digestible energy no higher than 0.9 Mcal/lb, an easy keeper that should weight 1100 pounds will meet that calorie requirement with just under 17 pounds of this hay a day.
The latest justification for the unlimited hay approach is that horses with restricted forage access will have “inflammatory, metabolic, endocrine, physiologic, and even hypothalamic damage in the brain”. Never mind that there is absolutely no scientific support for any of those things happening with reasonable calorie restriction in the horse or any other species.
The proof offered is from a NY Times article on what happened to contestants of the “Biggest Loser” (mistakenly referred to as “Greatest Losers”) six years after their stint on the show was over. It was stated, “Six years later, they were back to where they started, or worse, due to a shift in normal metabolism. ”
I didn’t fact check the quote from the NY Times as accurate because I prefer to get my information directly from the scientific articles. http://onlinelibrary.wiley.com/doi/10.1002/oby.21538/pdf. It was true their metabolic rate had reset so that they either had to exercise more or eat fewer calories than other people of the same weight to avoid gaining. However, to quote the study directly:
“While most subjects experienced substantial weight regain in the 6 years since “The Biggest Loser” competition, the mean weight loss was 11.9 ± 16.8% compared with baseline and 57% of the participants maintained at least 10% weight loss. In comparison, it has been estimated that ∼20% of overweight individuals maintain at least 10% weight loss after 1 year of a weight loss program. Only 37% of the lifestyle intervention arm of the Diabetes Prevention Program maintained at least 7% weight loss after 3 years, and 27% of the intensive lifestyle intervention arm of the Look AHEAD trial maintained 10% weight loss after 8 years .
Rapid weight loss, such as that experienced by “The Biggest Loser” participants, is sometimes claimed to increase the risk of weight regain, but recent studies have failed to support this idea since weight loss rate per se was not observed to affect long-term weight regain. The relatively greater success at maintaining lost weight in “The Biggest Loser” participants may have been due to the massive weight loss experienced during the competition since the magnitude of early weight loss is the best predictor of long-term weight loss. ……
In conclusion, we found that “The Biggest Loser” participants regained a substantial amount of their lost weight in the 6 years since the competition but overall were quite successful at long-term weight loss compared with other lifestyle interventions.”
Only two had gained back to their previous weight, one was continuing to lose and the others were as described. Their long term weight loss success rate was from 2 to 8+ times greater than more conservative approaches. [Note: Contestants calorie restriction was to 70% of requirements, which is considered mild in calorie restriction literature.]
To compare horses to Biggest Loser participants is ridiculous in the first place. Even obese horses don’t weigh 2+ times their normal weight and we don’t pull them out of the field to start a minimum of 2 hours/day of strenuous exercise. There are also huge differences between human and equine metabolic syndrome, and between individuals of both species that are obese vs obese and insulin resistant. The point though is that calorie restriction is not harmful and is necessary. Horses will be more successful simply because they don’t have to fight the biggest battle of all – will power.
It was conceded that leptin resistant horses on free choice forage could continue to gain weight for “a couple of months” or “even longer” without further stipulating exactly what that means. Even ignoring that there is no proof offered that truly insulin and leptin resistant horses will ever turn around on free choice forage, deliberately fostering further weight gain in horses that are often already obese, if not also laminitic so poorly tolerant of more load on their feet, is just not acceptable.
For 15 years I’ve been using a carefully mineral balanced, adequate protein, safe forage based diet fed at 1.5% of current body weight or 2% of ideal body weight, whichever is higher. It works just fine.
Eleanor Kellon, VMD