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How many calories do I need to eat on Wegovy?

Robbie Puddick
Written by

Robbie Puddick

Medically reviewed by

Fiona Moncrieff

8 min read
Last updated April 2024

Jump to: Should I buy Wegovy online? | How does Wegovy work? | How much weight will I lose on Wegovy? | Wegovy vs. Ozempic | Take home message

There’s no set calorie target whilst taking Wegovy, but you’ll likely be eating 1200-2000 calories per day whilst on Wegovy due to the impact of the medication on lowering appetite.

Wegovy interacts with the brain to lower appetite and reduce hunger, helping you eat fewer calories.

Additionally, you may find it challenging to overeat as this can cause more severe GI-related symptoms such as bloating, cramping, and even vomiting.

Wegovy can lead to GI-related side effects due to its impact on the gut. It slows gastric emptying (how quickly food leaves the stomach) and causes gut distension (an enlargement of the gut).

The symptoms related to these effects on the gut can be worsened by overeating whilst on Wegovy, leading you to lower your food intake naturally.

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What if I’m not eating enough on Wegovy? 

Some people on Wegovy will find the medication is so effective at lowering appetite that they struggle to eat enough calories to support their body’s primary functions, like digestion.

The first thing to do if this happens is speak with your doctor, or prescribing pharmacist who’ll be able to discuss this with you in more detail.

From a nutrition perspective, here are our top tips for eating enough calories on Wegovy:

  • Ensure a source of high-quality protein at every meal 
  • Eat three main meals a day, even if you’re not hungry 
  • Include high-protein snacks in between meals if your meal portions are very small 
  • Make food more palatable by seasoning to taste 
  • Make food easier to digest by cooking vegetables, mincing meat, and eating ‘softer’ foods 
Should I buy Wegovy online?

Wegovy is designed as an additional tool for weight management and shouldn’t be considered a lifelong medication.

Instead, it should be used to help you kickstart your weight loss and healthy journey while you commit to living a healthier lifestyle.

Ideally, we’d be able to lose weight without medication and lifestyle changes would be enough to support weight loss in the long term.

We’d generally recommend trying Second Nature’s weight-loss programme before considering a weight-loss jab.

Changing your habits is the most sustainable way to achieve long-term weight loss, and it’s also less expensive.

At Second Nature, we’ve been trusted by the NHS since 2017 to support people with type 2 diabetes and obesity to lose weight, manage their blood sugar levels, and lead healthier lifestyles for the long term.

In 2022, the NHS published data in the BMJ that compared the weight loss outcomes of five providers in the National Diabetes Prevention Programme.

Second Nature was more than twice as effective at supporting weight loss than the other four providers.

However, if you’ve decided to try Wegovy (when it’s available) but need support in making positive changes to your lifestyle, Second Nature could be an option for you. But it’s worth noting that we have strict eligibility criteria.

Otherwise, keep reading as we dig into the science of Wegovy and how GLP-1s work.

1) How does Wegovy work?

When we eat food, our stomach releases a hormone that helps the body regulate hunger and blood sugar levels. This hormone is called GLP-1 (glucagon-like peptide-1). The actions of GLP-1 are the target of Wegovy.

Wegovy and this class of medications are known as GLP-1 receptor agonists (GLP-1s). They mimic the actions of the hormone GLP-1.

Wegovy helps your pancreas release more insulin to lower blood sugar levels, delay emptying food from the stomach (also called gastric emptying), and lowers hunger by communicating directly with the brain’s appetite control centre, the hypothalamus, to lower food-seeking behaviours.

Click here to learn more about how GLP-1 receptor agonists like semaglutide work.

Key points:

  • Wegovy is a GLP-1 receptor agonist and mimics the hormone called GLP-1 to lower blood sugar levels by helping the pancreas release the hormone insulin
  • Wegovy lowers hunger by communicating directly with the brain’s appetite control centre, the hypothalamus. This action lowers food-seeking behaviour.
  • Wegovy also slows gastric emptying, which means that food will take longer to move from the stomach and through your digestive system

2) How much weight will I lose on Wegovy?

Wegovy leads to an average weight loss of 15-20% after 68 weeks and is more effective than other weight-loss injections, like Saxenda.

A meta-analysis investigated the impact of semaglutide (Wegovy) and liraglutide (Saxenda) and suggested that semaglutide was more effective at lowering blood sugar levels (as measured by HbA1c).

The study showed that a 0.5mg dose of semaglutide led to a more significant reduction (0.17%) in HbA1c than liraglutide.

The 1mg dose of semaglutide showed a further benefit compared to 1.2mg and 1.7mg of Saxenda at 0.47% and 0.3%, respectively.

However, the studies used to compare the two drugs were from individual trials, comparing one of the medications with a placebo (a sugar pill). They hadn’t yet been compared directly with one another.

Fortunately, a randomised controlled trial was conducted in 2022 investigating the impact of semaglutide and liraglutide on weight loss in individuals living with obesity.

The results showed that the participants in the semaglutide group lost 15.8% of their body weight compared to 6.4% in the liraglutide group.

Semaglutide was also shown to be more tolerated than liraglutide. 13.5% of participants in the semaglutide group discontinued their treatment due to side effects, compared to 27.6% with liraglutide.

Over 80% of participants in both groups reported common side effects and GI-related issues such as constipation, cramping, bloating, and diarrhoea.

Due to the positive results from these studies, Semaglutide was made available in 2023 in the UK after the U.S. approved the drug in 2021.

How does Wegovy compare to weight loss without medication?

Lifestyle interventions without semaglutide tend to lead to an average weight loss of around 5-10%.

Losing and maintaining weight loss of more than 10% is associated with significantly reducing complications related to obesity, including hypertension, type 2 diabetes, and heart disease.

A recent paper published in The Lancet showed that nearly 20% of participants in lifestyle interventions without medications gain weight, around 40% lose between 1-10% of their body weight, and just 13% lose more than 10%.

In comparison, less than 5% of participants combining semaglutide with lifestyle interventions gain weight, around 10% lose between 1-10%, and 87% lose more than 10%.

So, 47% more people lose more than 10% of body weight on lifestyle interventions with semaglutide compared to lifestyle interventions alone.

Key points:

  • A meta-analysis compared the impact of semaglutide and liraglutide on lowering blood sugar levels (measured by HbA1c) and suggested that semaglutide was more effective than liraglutide
  • A randomised controlled trial conducted in 2022 investigated the impact of semaglutide and liraglutide on weight loss in individuals living with obesity
  • The results showed that semaglutide was more effective at weight loss (15.8% body weight loss) than liraglutide (6.4% body weight loss)
  • Semaglutide was also better tolerated than liraglutide, with fewer participants discontinuing treatment due to side effects, but GI-related issues were common in both groups
  • Lifestyle interventions without semaglutide average around 5-10% weight loss, and less people achieve clinically significant weight loss without semaglutide

3) What’s the difference between Wegovy and Ozempic?

The only difference between Wegovy and Ozempic® is the available dose, with Wegovy available up to 2.4 mg, compared to 1 mg with Ozempic®.

Initial research on semaglutide focused on Ozempic® and doses between 0.5 mg and 1 mg. However, the studies found that 20-30% of individuals on the medication didn’t reach the treatment targets for reducing their blood sugar levels.

A randomised controlled trial with 961 participants compared the impact of a once-weekly dose of 1mg or 2mg of semaglutide on blood glucose levels and weight loss for people living with type 2 diabetes.

You might expect that a doubling of the dose would lead to a doubling of the effect.

However, the human body is a bit more complex than that. Medications (and hormones in the body) often have a ‘ceiling effect’ where the relationship between the exposure and the effect is no longer linear.

The results showed that 1 mg of semaglutide reduced HbA1c (average blood glucose) by 1.9% compared to 2.2% in the 2 mg group.

A similar trend was shown with weight loss. 1 mg of semaglutide led to an average weight loss of 6 kg compared to 6.9 kg in the 2 mg group. Interestingly, both groups reported similar levels of adverse events and side effects.

So, the higher dose of semaglutide that you’ll receive with Wegovy will likely lead to more significant reductions in weight loss and blood sugar levels without experiencing more adverse events or side effects.

However, you must monitor your medication responses and determine your tolerance level. You might tolerate a higher dose, but you might not.

The research on these medications has shown that the most severe side effects are reported when the dose of the medication is increased while your body adjusts.

You might determine that any side effects are worthwhile to help you improve your health conditions and lose weight. But you must contact your healthcare team and discuss any side effects to ensure this is monitored and the dose adjusted to suit your needs.

Key points:

  • Most research with semaglutide is with the doses of 0.5 mg, and 1mg that you have with Ozempic®
  • Only one trial has compared the impact of 1 mg to 2 mg of semaglutide and found it did lead to more significant reductions in weight and blood sugar levels
  • However, the differences weren’t as significant as you might expect and the dose that’s best for you will depend on your tolerance level and weight loss goals
  • You must report any side-effects with your healthcare team and adjust your dose accordingly

Take home message

The recent innovations in GLP-1 medications are pretty remarkable and have caused quite a stir in the world of healthcare.

We’re in new territory where obesity and type 2 diabetes medications treat an underlying cause instead of merely treating the symptoms to support better management.

However, these weight-loss jabs shouldn’t be seen as miracle cures; they’re not designed to be used for life.

They’ve been designed to be taken alongside lifestyle changes that will enable you to eventually come off the medications and maintain your lower weight for the long term.

The harsh reality is that we still don’t know the long-term effects of these medications on our health. There are examples of drugs being withdrawn from the market as more long-term data comes to light.

Lorcaserin was a weight loss drug approved by the Food and Drug Administration (FDA) in the U.S. but was recently withdrawn as data indicated that it increased cancer risk.

The example of lorcaserin is why you must weigh the pros and cons when your doctor prescribes medication or before you purchase it yourself and start treatment. Report any side effects to your healthcare team.

Wegovy has been shown to be safe and effective for most people in the short to medium term, but we don’t have long-term data to be sure they’re not causing severe adverse effects elsewhere.

At Second Nature, we’re not against using medications to support people in making healthy changes and reducing their risk of chronic disease.

However, we don’t recommend using medications as a reason not to make healthy lifestyle changes. The causes of obesity and type 2 diabetes aren’t merely rooted in biology but also in psychology and sociology.

With these medications, you may lose weight and reduce blood sugar levels. But will you be happier? Will you be more fulfilled? Will you be content with your life and social relationships?

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