By Dr. Danielle Keenan-Miller
Weight loss is the most common New Year’s resolution-- about 25% of all resolutions are focused on changing the numbers on the scale. While there is certainly no shortage of companies and individuals who will sell you on the idea that This is YOUR year, hardly anyone is honest about the truth-- weight loss resolutions don’t work. Not because you’re bad, or lazy, or helpless, but because you’re human. In fact, while many people can lose weight in the short term through restrictive dieting, almost all studies of long-term weight loss find that dieting mostly doesn’t work and very often backfires. Before you run screaming from this blog post, read on for a little more about the research on diets and how you can instead set a resolution that works for you.
Lots of evidence, looking at lots of different types of people, has shown how difficult it is to lose weight in a lasting way through dieting. A study in the UK  that followed 76,000 obese men and almost 100,000 obese women for 10 years found that just 1 in 1,290 men and 1 in 677 women obtained their desired weight-- and that included people who underwent weight loss surgery. The odds are better than winning the lottery, but not by much.
Even worse, it seems like dieting not only doesn’t work-- but that it can actually cause you to put on weight. A study  of 3,500 individuals found that people who went on a formal weight loss plan gained MORE weight than a control group that did not do anything to control their weight. Similarly, a 15-year study  of twins in Finland that found that people who went on a diet gained more weight over time than their identical twins that did not diet, even when they started at the same weight.
Our bodies are set up with a strong and complex set of biological, psychological, and environmental systems that fight against weight loss . A recent review of the dieting literature  found that 7 out of 10 studies that tracked people naturalistically over time found that dieters weighed more than non dieters; another 2 out of 10 showed no difference, and only 1 found lower weights among dieters. If you were offered a treatment that had a 1 in 10 chance of improving your condition and a 7 in 10 chance of making it worse, would you take it? What if that treatment also had serious side effects- it was difficult to do, would raise your level of stress hormones, and could have serious negative consequences for your overall health?
So, what are we supposed to do instead? Take a second to check why you want to lose weight, and see if you can achieve that underlying goal instead. Many people want to lose weight for health reasons, for example, to reduce the risk of developing type 2 diabetes. If that’s your reason, focus instead on behaviors that promote health, like eating more foods that help stabilize blood sugar, taking a walk after dinner, or monitoring your blood sugar levels more closely. If your goal is to have enough energy to chase after your kids, focus on building strength and stamina with exercise. Doing those things may or may not result in weight loss, but they will improve your health. The important thing is to measure your outcome in something other than weight. Refocusing your energies away from the scale and towards the goals that are going to be most meaningful and sustainable will stop the cycle of discouragement and set you up for lasting change.
 Fildes, Charlton, Rudisill, Littlejohns, Prevost & Guilford, 2015.
 French, Forster, McGovern, Kelder & Baxter, 1994.
 Pietiläinen, Saarni, Kaprio, & Rissanen, 2012
 Fothergill et al., 2016.
 Mann, Tomiyama, Westling, Lew, Samuels, & Chatman, 2007.