Why weight loss drugs are not a 'miracle' cure for obesity

Former commissioner of the American Food and Drug Administration (FDA) David Kessler is warning weight loss drugs, like the popular Ozempic, are not a miracle cure.

These drugs are classified as GLP-1 receptor agonists and were initially developed to treat diabetes. They contain active ingredients, like semaglutide, dulaglutide and liraglutide, which increase feelings of satisfaction or fullness by keeping food in the stomach for longer.

Although the FDA first approved a GLP-1 agonist for weight loss about a decade ago, the popularity of the drugs soared and shortages were reported in more recent years amidst celebrity endorsements from the likes of Oprah Winfrey and Elon Musk.

Related stories:

Ozempic is not approved to be used for weight loss purposes alone in New Zealand, but it is used to help people with diabetes. However, earlier this year, Wegovy was approved by MedSafe for weight loss.

Dr Kessler, who personally struggled with yo-yoing weight, has written extensively on the food industry's role in engineering addictive foods, which contributes to the obesity epidemic globally.

His new book Diet, Drugs and Dopamine looks at the new class of weight loss drugs, which he says “are not a miracle drug”.

“I have plenty of discipline but the one thing I couldn't control was my weight. I think the one thing we know from these new drugs, which have changed the landscape of weight loss, no panacea to be sure, but it's not willpower, it's biology at work," he told Nine to Noon.

He explains ultra-formulated foods are “engineered to manipulate the brains’ reward system” as well as hormonal circuits.

“I used to think ‘I lost the weight. I'm good. I'm done’. But then I'd always gain it back. In fact, now when I've lost the weight, I realise the work just begins because those addictive circuits, those hormonal circuits, those energy circuits, all [are] hardwired to come back.”

Humans evolved to deal with scarcity of food, not an abundance, by seeking out the sweetest and most energy-dense foods, he says.

“We put fat, sugar and salt on every corn and made it available 24/7, made it socially acceptable to eat anytime, certainly in the States, what did we think was going to happen?”

Three components that lead to addictions, and in turn obesity, are cue-induced wanting, cravings, and relapse, he says.

“I think if I were born two-three decades earlier, I would have probably been a smoker. I simply use these ultra-formulated foods to change how I feel, to focus my attention.”

However, Dr Kessler emphasises “weight is not the issue”, rather visceral fat which leaks out pro-inflammatory chemicals that affect our organs.

“That is in the causal chain of many chronic diseases, cardiac disease, kidney disease, diabetes. Doctors are just waking up to this fact. I think we've tended to treat these conditions piecemeal … but underlying all those conditions is this toxic fat.”

Our metabolism is becoming overwhelmed with ultra-formulated foods that there’s no doubt excess calories play a role in the problem of visceral fat as well as hyperinsulinemia (increase in blood of insulin levels), he says.

“Now it's very hard to sort out which comes first, is it the hyperinsulinemia - this elevated blood insulin - or is it this visceral fat? Or does this visceral fat cause this hyperinsulinemia?”

Dr Kessler acknowledges GLP-1 agonists represent a genuine breakthrough, but says experts still haven’t figured out how to use them long term.

“They’re only as good as long as you stay on it. It's so important that we understand that obesity, the weight, this visceral adiposity, is a chronic condition that needs chronic care or … we will regain the weight.”

The majority of people gain back 60 to 70 percent of their weight over time once they stop taking these weight loss drugs, he says.

While they can balance the reward circuit of our brain and gut with aversive circuits, they can also lead to complications in the GI tract from lack of mobility, he says.

“Some people who are on those drugs eat less than … 1000 calories a day, sometimes as low as 600 or 800 calories a day and that a state of semi-starvation and that can bring on its own set of complications.”

The drugs need to be used as part of a wider toolkit in treating obesity, he says.

“If you can figure out how to use that condition, if you can relearn how to eat, eat smaller amounts and eat healthier and that can carry over to when you're off these drugs, and if you use these drugs as one tool along with nutrition and behaviour therapy, along with physical activity - if you do this under good care with the help of a dietician or a nutritionist and a physician, then I think we are on the verge of reclaiming our health.”

He believes no progress will be made until we understand the addictive nature of certain foods.

“We don't have an end game. We don't have the data. How to use these drugs over a short period of time. Can I use these intermittently? What I resorted to doing is I take these drugs, I get the weight off. I try to do nutrition and behavioral therapy. I increase physical activity.

“I try to keep that conditioning and eat small, but over time … that conditioning fades and those addictive circuits come back and I'm back to myself. Then do I take go back on these drugs? And is it safe to go back on these drugs? And at what doses do I go back on these drugs? So there's a lot that we still have to learn.”