Ozempic – why diet still matters.

Core Nutrition Dietitians
Aug 14
5 min read

Ozempic has become one of the most popular and talked-about weight loss medication. Many people are seeing great results after years of struggling to lose weight. Ozempic is however not a quick-fix, it’s important to remember that without proper support, especially nutritional support, the results might not last after the medication is stopped. Research has shown that people are regaining weight after stopping the GLP-1 What is Ozempic?

Risk and side effects of Ozempic Ozempic (semaglutide) is a medication that was originally developed to treat type 2 diabetes. It belongs to a group of drugs called GLP-1 receptor agonists. It’s use was originally intended for adults with Type 2 Diabetes and for cardiovascular risk. Semaglutides have been shown to reduce HbA1c significantly in those with Diabetes. HbA1c is your average blood sugar level over 2-3 months.

This injection is given once a week at a small dose- which can be increased after 4 weeks. It is recommended that in side effects persist- you should return to the previous dose.

"Those taking Ozempic begin to consume less & less calories..." It works by reducing appetite, increasing satiety, improving blood sugar control slowing down the transit time of food through the gut. Those taking Ozempic begin to consume less and less calories- resulting in weight loss.

Large clinical trials (the STEP trials) have shown that people taking semaglutides lose on average 10–15% of their body weight, with some individuals losing even more when combined with lifestyle support (Wilding et al., 2021).

Taking Ozempic does come with risks and side effects. It is important to be aware of these before considering taking it.

The most common side effects include: Nausea, vomiting, diarrhoea, constipation, bloating and reflux. The severity of these symptoms usually worsens as the dose of Ozempic increases. More serious concerns include: Gallbladder problems, pancreatitis, potential thyroid C-cell tumor risk and worsening of diabetic eye disease in some people. Hypoglycaemia risk increases when used with insulin or sulfonylureas. Dehydration and kidney effects might occur due to gastrointestinal side effects. Before starting Ozempic it’s important to check bloods including HBA1c and renal function, and to review contraindications such as a family or personal history of thyroid cancer. After starting it is recommended to reassess glucose control, weight change and tolerability, If you are on medication for diabetes, it should be adjusted to reduce the risk of hypoglycaemia. Nutritional concerns about taking Ozempic

A lot of people taking Ozempic are not paying attention to the nutritional quality of their food, namely protein intake. Due to a decreased appetite, it is common behaviour to start skipping meals and not eating enough food to sustain basic basal metabolic requirements. This drives muscle catabolism and nutritional deficiencies. Because this drug is injected once a week, patients are reporting erratic eating behaviours- experiencing much lowesr appetite in the days following the injection and increasing appetite in the lead up to the next injection. Meaning- that in a full week, nutritional intake varies greatly from day to day.

"Eating habits and behaviour such as emotional eating, stress eating, binge / restrictive eating are not addressed by taking Ozempic alone."

It’s important to note that Ozempic does not cause nutrient deficiencies. Nutrient deficiencies can occur over time food diversity is limited and daily micronutrient requirements are not met. Common deficiencies include Vitamin B12, Iron, Calcium and Vitamin D. Magnesium, zinc, folate and potassium deficiencies might also occur if calorie intake drops too low. Symptoms like fatigue, weakness, poor mood or hair loss can often go unnoticed because it is often blamed on stress, hormones or busy schedules.

Common reasons as to why people of Ozempic are not eating enough protein include: feeling too full to eat/ nauseous from the medication, or if they are substituting balanced meals for snacks. Research shows that during weight loss, up to 25–30% of weight lost can come from lean muscle mass if protein intake and resistance exercise are inadequate. Loss of muscle mass lowers resting metabolic rate and increases the risk of regaining the weight lost. However, in a clinical setting, our practice has seen patients walk through the doors seeking help because more than 65% of their weight loss has been muscle. These patients are always those who were prescribed the drug by the doctor and have not received any guidance regarding lifestyle changes.

Studies consistently show that low fibre intake is associated with poorer gut health, higher cholesterol levels and worse blood sugar control. Fibre intake also plays an important role in managing constipation — a common side effect of Ozempic.

Eating habits and behaviour such as emotional eating, stress eating, binge / restrictive eating are not addressed by taking Ozempic alone. When the medication is stopped people may fall into the same eating patterns they had before. Many feel overwhelmed and unprepared when normal hunger cues return. Not having the tools to manage eating habits may result in regaining weight.

Considerations to make if you take Ozempic:

Try not to skip meals completely. Have full meals in smaller quantities (maintain a healthy balance between your meal components)
Try to eat at routine times throughout the day
If you are experiencing side effects, please talk to your doctor about your dosage
Dosage should not be increased sooner than every 4 weeks. Avoid increasing the dosage unnecessarily.
Find food alternatives with the same food group- if you have any food aversions
Prioritize protein-rich foods such as fish, chicken, eggs, plant-based proteins (legumes)… Some patient may want to consider a protein shake/ collagen powder.
Prioritize exercise

Why diet is essential when you take Ozempic

In a follow-up of the STEP 1 trial, participants regained approximately 67% of the weight they had lost within one year of stopping semaglutide, and many of the cardiometabolic improvements were also reversed (Wilding et al., 2022). This highlights an important reality: Ozempic does not permanently “reset” metabolic systems or eating habits. Without meaningful changes to diet, behaviour changes and physical activity, weight regain is common.

Feeling less hungry does not automatically mean the body’s nutritional needs are being met. Even when appetite is low, the body still requires adequate protein, fibre, vitamins and minerals to maintain muscle mass, energy levels, hormone function and overall health. Weight loss is only one part of the picture — good nutrition also supports blood sugar control, cholesterol levels, gut health, bone health, energy levels and mental wellbeing, all of which are just as important as the improved body composition on the scale.

While Ozempic can reduce appetite, it does not teach skills such as building balanced meals, managing hunger and fullness cues, preventing nutrient deficiencies, maintaining muscle mass long term, or navigating emotional and social eating. This is where nutritional guidance becomes essential. Working with a dietitian while taking Ozempic can help reduce side effects, protect muscle mass and improve the chances of maintaining weight loss once the medication is reduced or stopped.

What and how you eat can also significantly influence Ozempic-related side effects. Small, regular meals, adequate fluid intake, sufficient fibre and balanced fat intake can help manage nausea, constipation, reflux and bloating. There is no specific diet indicated when taking Ozempic, but outcomes improve when it’s combined with a reduced calorie, nutrient dense diet emphasising lean protein and fiber. A diet high in fat, refined carbs and sugar can worsen gastrointestinal side effects and lead to poor blood glucose control.

Ozempic can be a powerful tool, but it should never replace proper nutritional intervention. The most successful and sustainable outcomes are seen when long term results are prioritized (not short term). Whether you are considering Ozempic, currently taking it, or planning to stop- working with a dietitian can help protect your health, preserve muscle mass and support long-term weight maintenance — not just short-term weight loss.

References:

Wilding, J.P.H. et al. (2021) Once-weekly semaglutide in adults with overweight or obesity. New England Journal of Medicine, 384(11), pp. 989–1002.

Wilding, J.P.H. et al. (2022) Weight regain and cardiometabolic effects after withdrawal of semaglutide. Diabetes, Obesity and Metabolism, 24(8), pp. 1553–1564.

Hall, K.D. et al. (2020) Energy balance and body weight regulation. The Lancet, 395(10237), pp. 1768–1778.