If you've dieted more than once in your lifetime, you know that dieting is not often the hard part - keeping the weight off for good, is. Dr. Proietto, a physician at the University of Melbourne, decided to investigate why seemingly motivated people who can lose weight, can't keep it off. He decided that maybe the problem had something to do with the body's "biological state." He and his team recruited 50 obese men and women in 2009. Men weighed, on average 233 and the women weighed around 200 pounds. The subjects were put on very low calorie liquid diets plus some servings of low starch vegetables.
After ten weeks the average weight loss was 30 pounds. At this point of the study only 34 dieters remained committed and they received nutritional counseling by phone and in person to exercise and maintain a diet rich in vegetables and low in fat. After a year, most had gained back 11 pounds and reported feeling more hungry and pre-occupied with food than before they had lost the weight. What gives?
The researchers believe that even a year after weight loss, the subjects bodies remained in an altered state with hormone levels prompting them to feel as if they were starving. The hormone, ghrelin, along with peptide YY (which suppresses hunger) and leptin (a hormone that suppresses hunger and helps to moderate metabolism). These hormones seemed to be dramatically affected by the dieting process, and were in a "post-dieting" state with levels quite dissimilar to individuals who had never dieted. The net impact was to make dieters who lose weight then have to face a body chemistry that encourages, actually inspires weight gain. So one lesson to be learned from this observational study is that "avoiding getting fat in the first place" is a huge step to not having to face the difficult state of keeping weight off once you lose excess weight. It seems your body can be working against you.
Other studies seem to suggest that some of us definitely have a biological determinism that may make us more susceptible to gain weight, compared to others. Certainly some genetic predispositions have been found to be associated with obesity or body mass index. There is one genetic variant FTO associated with a higher rate of obesity. FTO may also be associated with food preferences, making those with the gene variant more likely to want foods high in calories and fat. On the other hand, confirming these biologic tendencies to someone could then instigate behaviors that cause weight gain. The person might think that they are not really doing anything to gain weight, "it's just happening." So they may disregard the reality that they are really eating more than they should, not moving enough and living a lifestyle that is significantly contributing to the weight gain.
Want to see what successful and sustained weight loss looks like?? Look no further than the National Weight Control Registry which tracks 10,000 people who have lost weight and kept it off for several years. You can register if you've lost 30 pounds or more and kept it off for a year. Most participants have lost on average 70 pounds and kept it off for 6 or more years. Methods used to lose the weight vary, though there are some consistencies on how they keep it off including: