The effect of weight loss by energy restriction on metabolic profile and glucose tolerance in ponies.

This research explores the effects of weight loss through energy restrictions on obesity in ponies, with a focus on the subsequent changes in insulin sensitivity and metabolic profile. The study found that a weekly weight loss of 1% of the pony’s ideal body weight improved insulin sensitivity and altered the metabolic profile of the obese Shetland ponies under study.

Study Design

• The study involved nine initially obese ponies.
• The weight loss was achieved through an energy restriction diet. The diet was initially 70% of maintenance energy requirements.
• To maintain a steady weight loss, the feed amount was gradually reduced to 50% and 35% of maintenance energy requirement during the trial.
• An oral glucose tolerance test (OGTT) was performed at weeks 0, 10, and 17 to assess changes in the ponies’ ability to manage glucose.
• Fasted blood samples were collected at weeks 0, 3, 10, 17, and analyzed for triglycerides (TG), non-esterified fatty acids (NEFA), creatine phosphokinase (CPK), lactate dehydrogenase (LDH), thyroid hormones T(3), T(4) and leptin, a hormone that regulates fat storage.

Results of the Study

• The ponies underwent an average weight loss of about 18.2%.
• Weight loss was associated with a decrease in the area under the curve for glucose and insulinrevealing an improvement in the body’s response to glucose and its utilization.
• Greater percentage weight loss was linked with a significantly lower glucose peak, indicating improvement in blood-sugar handling.
• The research found that the lower glucose response after the OGTT in lean ponies wasn’t the result of increased insulin secretion, but of improved insulin sensitivity. This suggests that the weight loss made them better able to respond to insulin, thus controlling blood sugar levels more effectively.
• Restricted feeding led to the mobilization of triglycerides (TG) and non-esterified fatty acids (NEFA), which are used for energy production during periods of dietary energy deficiency.
• Restricted feeding also led to a reduced basal metabolism as indicated by lower readings of LDH and CPK, enzymes related to muscle damage and thyroid hormones T(3) and leptin.

Conclusion

• The study concluded that in obese Shetland ponies, weight loss at a rate of 1% of their ideal body weight per week through energy restricted intake improved insulin sensitivity. This implies a potential strategy for managing obesity and improving insulin responsiveness in ponies.