Ok, you’ve lost the weight, so how do you keep it off ?
This question has been in the scientific circles forever and now we may see some clues as to why people yo-yo diet so much when weight fluctuates. The prevalence of overweight and obesity is increasing worldwide and coincides with the abundance of energy-dense foods and reduced physical activity, however, not everyone living in this obesogenic setting are obese.
So something else is going on……. Genetics. Results from twin, family and adoption studies have consistently estimated that 40-70% of variance in BMI in related to heritability. More research needs to be done to establish exactly what role the genes have and what can be done to affect obesity rates today.
Another weight determinant is hormones. Body weight is tightly regulated by hormonal, metabolic, and neural factors. When food intake is reduced, this leads to a negative energy balance that triggers a series of central and peripheral adaptive mechanism designed to prevent starvation. Leptin is a hormone that our bodies have to prevent starvation. Reduction in leptin, after energy restriction, leads to excess food intake, which can lead to weight regain. Insulin levels also decrease, slowing fat metabolism in an attempt to preserve energy stores. A 10 week study was done and researchers found that the high rate of relapse among people who have lost weight has a strong physiological basis based on long-term hormonal changes and is not simply the result of voluntary resumption of bad eating habits.
Unfortunately, adaptation doesn’t stop there. Also having an effect on weight is metabolic adaptation where there is a slowing of resting metabolic rate in response to a decrease in energy expenditure. This mechanism is to conserve body weight in the face of starvation and very log energy supplies. Research has found that formerly obese individuals had a 3-5% lower metabolic rate than did never-obese individuals. The more weight lost, the lower the metabolic rate so these professionals concluded that laziness is not a factor in weight regain. Neural factors also have an affect on weight regain by signaling that drives an increased consumption of energy to make up for the previous energy deficit.
Do you have trouble keeping your weight off? If you have any questions or need help with managing your diet for better health, get in touch!
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