The bulk of what I'm about to say concerns obesity toward the more severe end of the scale, particularly in people whose obesity is long term or lifelong. It isn't wrong if applied to merely being overweight, but it fits obesity better.
Over the past 30+ years I have in fact gone through a great deal of the research. I'm not putting myself forward as a genuine expert, but I have read widely. And purely from my own life, I have gone from above 100 kg down to roughly 70kg around 6 times. In 2012 I went from 122kg to 65kg and held that for a couple of years, yet by 2022 I was 145kg, then reached 75kg in 2023 and remained there for a year with no GLP drugs. Reading this forum tells me this is an extremely common story among people whose obesity is more severe; not everyone follows that pattern, but it is common. What I've found about holding weight off without GLP drugs is that it is genuinely hard, even when the diet is purpose-built to keep hunger low - very high protein at 40-50% of calories, low calorific density, very low fat, and zero foods that are high glycemic index / highly rewarding / high calorific density. Staying weight neutral demanded 1600-1800 kcal/day, while my body kept signalling it needed more calories; I was hungry once I finished eating and pretty much all the time.
As I see it, and I believe this lines up with the research, deliberate conscious calorie restriction or cognitive restraint over intake is almost always unsustainable. Yes, every single action anyone ever takes can be consciously controlled, but doing this takes mental effort. ( Most people most of the time are eating more on instinctive or emotional cues without a lot of conscious thought involved ) . No one likes to believe that sort of mental effort is a finite resource, yet it has been shown many times in relation to food intake and many other situations to actually work that way: over time the ability to sustain that effort wanes and weakens, even with huge effort life can get in the way and provide extra stresses that reduce the ability to sustain that effort, and so over time nearly everyone falls back eventually into more instinctive older patterns of behaviour whether they want to or not, end up eating more and regaining weight. A very few manage to translate this effort into new habits that no longer require constant effort to maintain, and some people are just extremely strong willed and these are the very few that can keep weight off long term without outside interventions like drugs or surgery. But I do believe that in general it only works when the mental effort of that choice is minimal as the habits get firmly established and instinctive.
What I say on this issue generally does not appear in the literature; these are my opinions, drawn from personal experience, a lot of forum reading and reading the papers. Obesity researchers are simply not going to come out and declare that the dominant treatment plan for obesity since forever is a failed therapy, in the same way that dietitians and nutritionists are going to be very skeptical of GLP's, because it threatens their world view.
So diet and exercise can be made to work, but the success rates are awful, maybe 5-10% sustain large weight losses and keep it off, so describing a treatment with a success rate that low as a failure is not wrong. It is not that it cannot work, it is that in real life it is so rare for it to work that it is just not a worthwhile approach, especially now there are finally better options. GLP drugs for obesity have success rates nearly the opposite, where only 5-10% fail to lose significant amounts of weight, and with tirz or reta, the average weight loss is 25%+, this is totally unprecedented in terms of drug treatment for obesity, and though the research has yet to catch up with the forums and experimental use much higher weight losses have been achieved with higher doses and combinations, as well as at standard doses in those who respond especially well.
Maintenance on GLP's is the only experience I have with them; I never used them to lose the weight. Even the mild reduction in appetite from low dose ozempic with nausea and malaise for a year was preferable to the chronic hunger from trying to keep the weight off without it. Thankfully I became aware of other options, and at this point I am close to achieving what I would have thought impossible, a balance between hunger and the number of calories required to not put on weight, so that with only effort at choosing food types to eat, but not amounts, I can eat when hungry and not gain weight. This has very definitely never been the case ever in my life before. It requires tirz15mg/reta5mg/cagri0.5mg/week, and I do have to put up with some side effects and cannot increase doses of any of them at all without much worse side effects, but compared to being permanently hungry it is a much more tolerable state and I think has good odds of working long term.
For my part, I think most people using GLP's to lose weight who believe stopping them will work without regaining weight are indulging in wishful thinking. Most of the time if you have healthy eating patterns and exercise and have the right genetics, you will not become obese in the first place. Once this has happened , it is a different story, and I think there is good evidence that the appetite regulation system in severe obesity especially is fundamentally broken in ways that are not currently understood.
There are a lot of difficult to control forces pushing towards weight regain in the weight lost state, the only thing that currently exists that solves this reliably is GLP drugs, so I think keeping an open mind about their ongoing use is a good idea. Unfortunately obesity is a topic with a lot of bias, bigotry and negative attitudes attached, so it can be difficult to accept that staying on the drugs long term might be needed. No one seems to care about having to stay on blood pressure or cholesterol or diabetes medications long term, and the issues are really very similar, a complex metabolic system with lots of control systems/chemicals/hormones, that can go wrong, and that long term treatment massively reduces long term adverse health consequences, and GLP drugs are really not much different, except for the emotional issues about self control , and the idea that you should be able to control weight by willpower alone, despite the evidence that this does not really work.
