But They Said "Science!"
There are so many different ideas out there when it comes to weight loss. It has gotten to a point where claiming a "scientific" foundation to whatever approach you are using has become both normal and so very meaningless. Here is how to determine whether or not to buy in to the "science" behind the claims, what determines a good plan and what is theoretical at best.
The problem with most plans that claim a scientific foundation is that they lack EVIDENCE. To be truly scientifically validated, the plan needs to have been tested and well designed research studies. The problem being when you look at the "science" behind a lot of plans what you actually see is a lot of THEORY. It's usually along the lines of "based on this scientific fact we know from some other unrelated application, we assume that XYZ is true which makes this the perfect diet/exercise/weight loss plan!" The problem is, they don't have any applied research to show whether or not their theory is true. Theories are wonderful, they are an integral part of the scientific process, however a theory is JUST an idea someone has and is NOT proof that it is true.
Another big cause of false beliefs in nutrition and weight loss is mistaking correlation and causation. Looking at trends over time and assuming that since X and Y increase together, that must mean X causes Y. But that's only one possible explanation- Y could have caused X, there could be some other factor Z that caused both, or even it could entirely be a coincidence. Unless you control the variables, you have no way of knowing and any conclusions you draw are...theories.
Some theories end up getting tested and shown to be true. Others, not so much. Just take a look at low fat diets and now low carbohydrate diets. There were what seemed like reasonable theories behind both, but the actual controlled research studies again and again show that what causes weight gain is calories regardless of whether they come from fat or carbs and that reducing either one when the calories are the same typically makes no difference.
Next time you see someone talk about the "science" behind a plan they support, be a critical thinker. You want to look for "evidence based" and also want to make sure the evidence being cited is reasonable- controlled studies in humans. Many people try to claim "evidence based" when the studies were done on rodents or when they are citing correlational studies they aren't using solid evidence. Keep in mind that a lot of theories that seem to make sense can even be harmful. Be hesitant to try anything that feels extreme, punishing, overly difficult, or a vast departure from the well known moderation, balanced diet, spend more time moving your body ideas we know as fact. If it sounds too good to be true, it usually is, even if the "science" cited tries to tell you otherwise.
Sticking to moderate plans and looking for real evidence can save you not only time and energy but can also protect you from unintentionally damaging your body.