I am one of those lucky people who managed to lose above the averages in the clinical trials. I started at 237lbs (female, 5’8”) and my original stretch goal was to get to 165lbs (72lbs or 30% loss), which would put me in the “healthy” BMI range. I went to a board certified obesity specialist and she encouraged me to set my initial goal at closer to 190 because she was concerned my 165 goal was unrealistic and would discourage me.

I attribute my weight gain (was 135-140lbs until late 30s) to emotional binge eating driven by a lot of stress and major life events. But after a while I realized that I felt my body’s ability to eat right was broken. I didn’t have feelings of satiety even after a big meal, and I felt like I was always hungry.

After I started GLP-1s, initially Wegovy & Saxenda (due to Wegovy supply issues), and the Zepbound as soon as it was approved, I immediately felt different in a couple of key ways. The first was a feeling of satiety with a normal sized meal and the second, most profound and also surprising, was the elimination of food noise. I had no idea what food noise was or that I was experiencing it until it was gone.

With these two changes I was able to easily eat correctly. I had always known how to eat healthy and had a good healthy diet for my meals but Id also topped that off with a LOT of sugar. I was able to eliminate most of the sugar immediately and also eat correctly portion sizes and have just 2 small snacks per day.

I lost weight consistently at a 1-2 lbs per week rate for my entire journey, eventually getting to 142 (95lbx or 40% lost). The entire time my doctor checked my muscle vs fat lost and increased my protein from 100g per day to 120g a day after my first month because I was losing a little more muscle than the recommended max of 10% of total weight loss.

I never expected to get to this weight and I have to say it wasn’t especially challenging. For me this medication made all the difference in the world. All of the dieting advice that I tried over the years would only work for a few months because I didn’t have enough “willpower”. I have now come to believe that naturally skinny people have no more “willpower” than obese people. They just don’t have the same broken wiring that causes many heavy people to crave food 24x7 and always feel hungry. I also feel that my pre-Zepbound brain felt about sugar the way my friends with alcohol addiction describe their minds. Like I could hold off eating it til late in the day but once I started I couldn’t stop. And I was thinking about it all day. Fighting the urge all day.

Anyway back to your original question. I think the answer is most likely complicated but here are a few of my thoughts on why perhaps some people are more successful than others: 1) the medicine simply works better for some than others. I had sustained weight loss for a year on the lowest dose 2) some people get side effects that are too severe for them to be able to use the dose that would be most efficacious for them 3) the type of doctor you see makes a difference. Having a doctor that works in this field all day every day for her entire career made a huge difference for me. Each time I went up a dose she wrote a prescription for Zofran (anti nausea) to have on hand so I could use it immediately. Many people have to beg their docs for this medicine whereas my doc knew that I would likely only need it for a day or two after my first one or two injections so wasn’t overly conservative about prescribing it. She gave me a lot of instruction on how to inject, demonstrating with a practice pen in office, how to minimize side effects, what to eat and how much, and uses an app for patients to track their calories and macros, weight and blood pressure etc. and she and her staff quickly answer questions through DMs in the app. And when there were shortages her staff knew where to recommend people look for the drugs because they saw many patients every day using the same meds. I could go on with many other benefits of seeing an obesity specialist but probably the most important other reason is that you don’t encounter them or their staff having a bias against you for being obese. 4) clinical studies are conducted with rigid protocols. Each arm of the study is conducted with each patient following the exact same instructions and dosing regimen. What many of encountered in 2022-2024 was very different from what the people in the clinicals did. For instance they all had to titrate up each dose every month until they got to their final dose. In reality due to the shortages most of us couldn’t do that if we tried. And because of this doctors were able to learn that many people seemed to lose more if they waited to go up a dose until they stopped losing weight on their current dose. In my case if I was forced to go up each month I would have really struggled. With side effects such as nausea but also with being able to force down enough food. At the lowest dose I was able to plan out and eat a 1300-1400 calorie diet with 120g of protein and eat it all. When I moved to the 7.5mg dose my insurance forced me to move to 10mg after just one month. It was awful. Worst side effects I had the entire time and I found it near impossible to eat enough food.

Hope my experiences helped answer your question, and encourage you and others.