Foods to avoid during weight loss treatment: a practical guide

There are several ways that the food you eat can impact your weight loss treatment.

• Consuming too many calories: Weight loss medicines are designed to help you consume fewer calories, but if you exceed your calorie limit, it could affect your progress.
• Impact on metabolism: A diet high in sugary and fatty foods can affect your metabolism, making it easier for your body to store fat.
• Increased cravings: Giving in too frequently to cravings could lead you to consume more calories, which could reduce your weight loss efforts.

Some weight loss medicines have specific foods and drinks you should avoid. This is because they can cause side effects.

Weight loss medicines work by reducing your appetite - but you still need to make healthier diet choices like consuming fewer calories and making healthier choices to get the most out of your treatment

Dr. Caroline Fontana Lead Prescribing Doctor

Two weight loss medicines that have specific interactions are Mysimba and Orlistat.

To get the most out of your weight loss treatment, here are 5 foods to avoid eating too much of.

Caution

Always ask your doctor before making big changes to your diet, as they may need to monitor you.

1. High-fat foods

Foods that are high in fat can impact your weight loss. High-fat foods tend to be higher in calories, so eating too many can mean you go over your daily calorie allowance.

These foods also tend not to be very nutritious. They don’t include many of the beneficial nutrients that help you feel full and be healthy.

Foods high in fat include:

• fried foods like fried chicken, fish or chips
• fatty cuts of meat like pork belly, beef ribeye or chicken thighs
• meat products like sausages or pies
• butter, ghee or lard
• hard cheeses like cheddar
• cream products like sour cream or ice cream
• savoury snacks like popcorn, crackers or crisps
• chocolate, biscuits, cakes or pastries
• products containing palm oil
• coconut oil or coconut cream

These foods are also high in saturated fats. Consuming too many of these foods can put you at a higher risk of high cholesterol, which can lead to serious heart conditions in the long term.

2. Refined carbohydrates

Carbohydrates are an essential nutrient and the main source of energy. However, some carbohydrates are refined and processed in a way that removes the beneficial nutrients like fibre. These are known as simple carbs or refined carbs.

They provide little nutritional value and are higher in calories, so they can cause weight gain if you eat too many.

Refined carbohydrates include:

• white bread
• pasta
• white rice
• white flour
• pastries or cakes
• packaged breakfast cereals
• carbonated or sweetened drinks like fruit juice

As well as causing weight gain, too many refined carbs can cause high blood sugar levels.

Eating too many refined carbs can cause your blood sugar to spike. If your blood sugar spikes too often, your body starts producing too much insulin.

Over time, this can cause your cells to stop responding to insulin, which can lead to insulin resistance. This is a risk factor for type 2 diabetes and further weight gain.

3. Sugary beverages and alcohol

Many people forget that what they drink also affects their diet. Sweet beverages and alcoholic drinks are often high in sugar and calories, even though they don’t feel like it. So, drinking too much can subtly damage your weight loss efforts.

Some drinks you should consume in moderation include:

• alcoholic drinks like wine, beer, cider or cocktails
• fizzy drinks, including “diet” drinks
• fruit juice
• sweetened coffee drinks
• energy drinks

Important:

The effects of alcohol can also make the side effects of any weight loss treatment worse, especially if you are on Mysimba.

4. Ultra-processed foods

Ultra-processed foods, or UPFs, are food products that have been industrially manufactured. This means they go through many processing steps and contain ingredients that aren’t common in home cooking (e.g. preservatives or artificial sweeteners).

These foods tend to be high in calories but contain very little nutritional value. So, they are big causes of weight gain.

Common ultra-processed foods include:

• processed meats like ham & sausages
• mass-produced bread
• breakfast cereals
• instant soups
• crisps
• biscuits
• ice cream
• fruit-flavoured yoghurt
• fizzy drinks
• alcoholic drinks

More than half of the calories an average person in the UK eats and drinks come from processed foods, according to research. They are usually quick, convenient and tastier options than cooking.

But these foods should be eaten in moderation and swapped for minimally processed or unprocessed foods where possible. Too many UPFs could lead to more weight gain and affect your weight loss efforts.

5. ‘Low-fat’ products

You may see the label ‘low-fat’ and assume it’s the healthier option. However, a lot of times, they are not as healthy as they seem.

Products that are marketed as ‘low-fat’ mean they contain 3 g of fat or less per 100 g. However, these products often contain other ingredients to make them taste nice, such as added sugar or artificial sweeteners.

Products that often have low-fat alternatives include:

• yoghurts
• cream
• cheese or cream cheese
• desserts
• premade sauces

You should always check food labels to see what they contain. Foods that are high in calories or contain too much sugar may harm your weight loss efforts.

This may seem like an overwhelming list of foods to consider. But a few mindful food swaps will help you get the most out of your weight loss treatment.

Nutritious foods

The best foods while on weight loss treatment are nutrient-dense and whole foods.

These foods contain essential nutrients like protein, healthy fats, fibre, vitamins and minerals. They also tend to be lower in calories, which means you get the nutritional benefit without consuming too many calories.

• fresh fruits
• fresh vegetables
• lean proteins
• healthy fats
• whole grains

Nutritious and whole foods also help you feel fuller. This means you are less likely to have cravings between meals. This is very beneficial if you are using weight loss treatments.

Hydration without the calories

Another easy fix is what you drink. If you’re having a fizzy drink or a glass of wine every night at dinner, that could significantly impact your weight loss treatment.

The best fix is to drink more water. Water has no calories, and some evidence suggests water can reduce cravings. Staying hydrated is also important for your overall health.

Important:

To stay hydrated, you need to drink 6-8 cups of water a day.

If you fancy something with a bit of flavour, you could try:

• water diluted with flavoured squash
• black tea or coffee
• herbal teas

If you have tea or coffee, you should try not to add sugar or switch it out for sweeteners like stevia.

Healthy food swaps

There are some simple swaps you can make to make your diet more nutritious.

4 healthy meal swaps

Non-nutritious option	Healthy swap
Breakfast cereal	Bran cereal with berries
White bread sandwiches	Whole-grain bread sandwiches
Ice cream	Greek yoghurt bowl with fruit and nuts
Chips	Roasted sweet potatoes

If you’re still feeling peckish between meals, here are some healthier snack options to try:

• roasted chickpeas
• dark chocolate
• nuts like almonds
• hard-boiled eggs
• chopped fruit

These snack ideas are whole foods, less processed and are more filling than regular store-bought snacks.

Starting weight loss treatment is not a simple diet change; it requires a whole lifestyle change. Here are some tips to support this lifestyle change.

Plan your meals in advance:

Plan your meals each week and make a shopping list, this way you can control what you eat and you’re not tempted to get takeaway or buy snacks.

Read food labels carefully:

You don’t need to count every calorie, but checking food labels will help you know what they actually contain and make better choices.

Manage emotional eating triggers:

Studies show that almost 50% of overweight people struggle with emotional eating, so it’s important to understand what causes you to emotionally eat and manage it.

These lifestyle changes will help you stick to your diet and see progress while on weight loss treatment.

Starting weight loss treatment is a whole lifestyle change, and it can feel pretty daunting. But making simple food swaps and cutting down on unhealthy foods and drinks will help you see results.

Don’t get discouraged! It takes time, trial and error to learn what works for you. Just enjoy the process of feeling and being healthier.