Experts warn that without personalised support, people taking GLP-1s could be losing out on key nutrients.
With medications like Wegovy and Saxenda now available on prescription for weight loss in New Zealand, there’s more interest in GLP-1s than ever.
But experts warn that without personalised support, those taking them - women in particular - could be losing out on key nutrients.
International research suggests
“We’re seeing people experiencing these nutrient deficiencies, but also muscle loss and reduced bone density,” says Dietitians New Zealand spokesperson and registered dietitian Lily Henderson.
Weight loss drugs can be prescribed by your GP if you meet certain criteria, with BMI, age, and health issues such as diabetes or high blood pressure taken into account, and haven’t seen weight loss as a result of lifestyle changes. They are not funded in New Zealand and can cost up to $600 a month.
Henderson says that while New Zealand doesn’t yet have strong data on just how popular they’ve become here, she and her colleagues are seeing more and more people wanting to access them.
“The key thing that’s being left out at the moment is the long-term outlook in terms of an individual’s health - what wraparound support is there for the individual to build these sustainable habits and incorporate those while they’re taking the medication,” she tells the Herald.
“These are effective tools, but they’re not a silver bullet. How can we ensure that we’ve set people up for success and support them with good nutrition and an overall healthy lifestyle?”
GLP-1s work by mimicking the gut hormone glucagon-like peptide 1.
“They suppress our appetite, reduce our food noise so we’re not thinking about food. They slow down our digestion, so we feel full for longer. And then they work on the pancreas and stimulate the release of insulin, so they help us to manage our blood sugars a lot better,” Henderson explains.
But effective as they are for weight loss, she says, “just because we’re eating in a different way, it doesn’t mean that our bodies’ nutritional needs change”.
Christchurch-based registered nutritionist and resident nutritionist for women’s wellness brand Everee Women Victoria Biddick says professional advice is key in getting the best results from weight-loss medication.
“Depending on which drug you’re on, [you’re] going to reduce your daily energy intake by about 19 to 39%. And while that’s going to give you weight loss, it’s going to make it challenging for you to get your nutrition requirements from food alone,” she tells the Herald.
“For women especially, we’d be thinking about your calcium, iron, magnesium, zinc, and different vitamins. We wouldn’t want to drop lower than about 5000 to 6000 kilojoules a day, because if we go lower than that, we risk having some deficiencies.”
Biddick suggests people might find it easier to have six smaller meals each day, with reminders on your phone, fridge or bag, since you won’t get the normal hunger cues.
Without those cues or “food noise”, people have an opportunity to make a shift towards wholefoods, she says. If you’re eating less, then what you are eating needs to have enough nutrients.
“Fruits, veges, proteins ... they’re going to give you bang for the buck. Adding in healthy fats and seeds are really good ways to make smaller portions of food more nutrient-dense and give a bit more energy in terms of calories.
“The way we protect our muscle loss is we make sure we have enough dietary protein ... lean meat, fish, low-fat dairy products, plant-based proteins. Combining those with some resistance training is important, because that helps the muscle do its thing.”
Most of us already aren’t getting enough fibre. Biddick suggests gradually increasing your intake by choosing brown rice, grainy bread, pulses, chickpeas, chia, pumpkin and sunflower seeds and keeping the skin on your fruit and veg.
Opt for healthy fats such as olive oil, nut butters and avocado. Calcium is another essential, particularly for women as they age.
“Most nutritionists I’ve talked to [are] really worried about long-term, especially for women, frailty and osteoporosis. That means we need to focus on those low-fat dairy products. If you’re a plant-based eater, you can get it from nuts and seeds, broccoli, tahini.”
Hydration is also important, because when you’re eating less, you’ll be getting less of the water content from your food, though it’s best to limit tea, coffee and especially alcohol.
Lastly, if you’re on weight-loss medication, it might be worth getting some advice on exercise from a personal trainer.
“Start small and slow ... it can be very simple, like sit-to-stand activities as a starting point. Resistance [training] is best, but it needs to be at the level where the person’s at,” Biddick says.
“The goal isn’t just weight loss, it’s actually a foundation for long-term health and wellbeing. Often, we think we want the quick fix without thinking of the repercussions.”
Henderson agrees that help from health professionals is “really key”.
“They will need to ensure that the benefit of the medication outweighs any of the risks or the side effects that you’re experiencing.”
Side effects experienced while taking GLP-1s are often gut-related – nausea, constipation, diarrhoea, reflux.
“Those side effects are probably going to reduce food intake further and impact the quality of your diet. You’re probably not going to be reaching for a nourishing meal when you’re feeling really nauseous,” says Henderson.
She notes that side effects tend to let up over time, but it depends on the dose you’re on.
According to Ministry of Health clinical guidelines for health practitioners around weight loss management, “people should always use weight-loss drugs in conjunction with lifestyle changes”.
Henderson points out, “It’s hard to say what support is being offered by GPs, but we can assume it varies.”
Having access to that additional support will also depend on the individual and their budget, whether it’s diet or exercise-related.
As for the psychological impacts of using weight loss drugs, Henderson says the research is mixed but it could be an isolating experience for some.
“Another area that probably gets overlooked is just how these medications impact an individual’s psychological health, but also their ability to socialise and eat food with others. We know that’s really important for connecting with people ... also how it affects their relationship with food.”
Then there’s the question of what happens when you stop taking the medication, and your appetite goes back to normal.
Henderson says a large proportion of people stop taking the medication within 12 months - some research suggests between 20 and 50% - and most people will regain some or all of the weight they’ve lost, often rapidly and more likely fat than muscle. Studies have found patients can regain as much as two-thirds of the weight they lost, if not all.
“There is also a bit of debate around whether these medications are a long-term, life-long solution, or should be viewed as a tool to support people to make changes with the view of tapering off,” she adds.
In the UK, guidelines released in August this year recommend that those coming off weight-loss drugs need support from their GP for at least a year, to help them minimise weight regain and maintain a healthy lifestyle.
According to Healthify He Puna Waiora, “ongoing monitoring and support from your healthcare provider for at least one year is crucial to help you maintain any positive changes you have made.
“This may include support from a health coach, health improvement practitioner, nurse, doctor, dietitian, nutritionist or local weight management, exercise or support programme.”