What happens if you take Orlistat without eating?

Unless you've been living completely off-grid, you will have seen or heard discussions about different weight loss medicines. There's so much information (and misinformation) to wade through online, it can be hard to know what's accurate.

Whether you're just starting your weight loss journey, or you've been working towards your goals for a while, we're here to help untangle some of the facts.

In this article, we'll take a look at how Orlistat works, things to know, and how to get the most out of your treatment.

What is Orlistat?

Orlistat (sometimes known by its trade names Alli or Xenical) is a medication that can help with weight loss or weight management — usually as part of a treatment plan developed by your doctor.

It can help with initiating weight loss, maintaining a healthy weight, or preventing weight gain again [1].

Before taking Orlistat, you should chat to a GP, pharmacist, or healthcare professional about whether it's the right medication for you. It's most commonly recommended for:

• People with a BMI of 28 or above who might be at risk of certain health conditions, such as type 2 diabetes or high blood pressure
• People with a BMI of 30 or above [2].

Orlistat is different to other weight loss medications in that it doesn't affect your appetite — it won't stop you from feeling hungry or make you feel full [3]. So, how does it actually help with weight loss?

How does Orlistat work?

Orlistat is a type of medication known as a lipase inhibitor. This means Orlistat works by preventing your body from absorbing the fat in the foods you eat [1].

After a meal, the fats we eat are broken down and absorbed with the help of things called lipase enzymes. When used correctly, Orlistat blocks these enzymes and instead lets the fat pass through your digestive system [1].

Normally when you eat a meal, your body absorbs the fat content from the food you eat. Orlistat prevents your body from storing this excess fat from meals and stops about a third of it from being absorbed [3].

Your body then gets rid of the undigested fat via your poo/bowel movements, meaning it can't store it as extra body fat.

This can help you lose weight you're already carrying, but also prevent you from gaining weight [1].

As with all weight loss treatments, it's important that you use Orlistat as one part of your overall plan — which should also include a combination of healthy diet and exercise goals. This could look like a reduced-calorie diet, and finding a type of regular exercise you enjoy.

Who can use Orlistat?

Research suggests that Orlistat is usually well-tolerated, meaning most people can use it without too many side effects. There are a few things to consider before starting Orlistat though, and you shouldn't take it if [1]:

• You have chronic malabsorption syndrome (where your body doesn't absorb nutrients as well as it should)
• You have a blockage in your bile duct (called cholestasis)
• You're pregnant, breastfeeding, or trying to become pregnant
• You're under the age of 18

If you have any of the following health conditions you should speak to your GP, pharmacist or prescriber before starting Orlistat:

• Diabetes
• Chronic kidney disease or history of kidney stones
• High blood pressure [3]
• Allergies to any medicines, foods, preservatives, dyes or other allergies [1]
• A history of stomach ulcers or gallstones
• Have any other health issues [4]

Like with most medicines, you should never stop taking Orlistat suddenly, or without advice from your prescriber [1].

Why you need to eat before taking Orlistat

Aside from knowing the ins and outs of how Orlistat works, it's also important to know how to take it properly and get the most out of the medication.

If we can leave you with one piece of crucial advice: it's remembering to take Orlistat when you eat a meal, or soon after.

Orlistat can only do its job when there's dietary fat present in your body. This means you should take it with each of the 3 main meals a day, e.g. 1 capsule at breakfast, lunch, then dinner [1].

The good news is that it can still be taken up to an hour after you've eaten, but it needs to be taken every day to be effective.

If you miss a meal or eat a meal that has no fat, you don't need to take your next dose (keeping in mind that most meals have at least a small amount of fat) [1].

What happens if you don't eat before taking Orlistat?

If you take Orlistat on an empty stomach, you're more at risk of experiencing side effects. These can include:

• Increased farting (flatulence)
• Stomach pains or cramping
• Needing to poo more often
• Needing to poo urgently
• Oily stools, looser stools than usual, fatty or liquid stools
• Oily spotting or oily discharge from the anus
• Pain or discomfort in the rectum [1] [2]

Some of these side effects can happen when you're first prescribed Orlistat, or still getting used to a low-fat diet.

Loose oily stools are more likely to appear after eating high-fat foods — so it's important to follow your doctor or health professional's advice on what changes you might need to make to your diet while taking Orlistat [1].

Are there any foods you should avoid while on Orlistat?

To help Orlistat be as effective as it can be, it's a good idea to avoid high-fat foods, especially in between your meals. This means trying to reduce snacking on things like chocolate, biscuits, or other savoury snacks [1].

While you're taking Orlistat, it's important to have a balanced diet that includes lots of fruit and vegetables.

Additionally, you should try to spread out your intake of fats, carbohydrates, and protein across your 3 main meals a day [4].

Sometimes when you're trying to lose weight you can start lacking vitamins and minerals. Even if you're eating a healthy diet, people taking Orlistat might need to take a multivitamin supplement [4].

Orlistat can affect your absorption of fat-soluble nutrients, so taking a supplement that contains fat-soluble vitamins can help. These supplements need to be taken at least 2 hours before or after your Orlistat, or when you go to bed at night [4].

Other wellness tips while taking Orlistat

According to the experts, other tips can help with your weight loss goals while taking Orlistat. Here are a few things you can try:

Diet tips

• Cut off any visible fats from your food (e.g. skin off chicken, fat off meat)
• Try to eat 3 regular meals a day, to help reduce snacking
• Aim for less than 40-50 grams of fat a day
• Switch to low-fat options e.g. light cheese, skim milk, or low-fat yoghurt
• Reduce the amount of high-fat snacks or takeaway you eat
• Instead of frying your food, try baking, stir-frying, or grilling
• Use only thin layers of butter or margarine
• Avoid creamy sauces and dressings (like mayonnaise)
• Keep an eye on portion sizes, or use a smaller plate to serve your food
• Read the labels on your groceries, and look for foods that have less than 5 grams of fat per 100 grams where you can [1]

Staying active

A healthy diet is one part of the equation, but to lose weight you'll need to explore an exercise routine that works for you.

If you're new to exercise, or returning to it after having a break, it's usually recommended to start small and work your way up. This could look like going for a walk for 10 minutes a day at first, eventually stretching it out to a longer walk when you can [1].

A healthy exercise plan means trying to be active in some way on most days of the week.

This can be any activity you want — jogging, going to a gym class, swimming, mowing the lawn, playing a team sport, or taking the stairs instead of the lift. Ideally, you should also try to include muscle-strengthening activities where possible [5].

The most important thing is to move your body in a way that feels good to you and reduce the amount of time you spend sitting [5].

Before you start any type of exercise program, make sure you discuss a realistic and healthy weight loss goal with your doctor. They can recommend a good place to start — that takes into account your health, lifestyle, and other individual factors.

Where to get help with weight loss

If you're interested in learning more about Orlistat or other weight loss medications, such as Wegovy and Mounjaro, our team can help you choose the best option for you.

We're also here to help with your weight loss goals in general. Juniper has lots of treatment options depending on your needs.

Juniper’s Weight Reset Programme gives you access to expert advice from our trained clinicians, dieticians, and nutritionists, as well as top-tier health coaches. We're here to support you, no matter where you're at in your weight loss journey.

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