Is there a link between food allergies and weight gain?

Starting any new diet, particularly a weight loss journey, can be more complicated if you suffer from a food allergy or food sensitivity.

Suddenly, you're left checking the lengthy ingredient lists of every food, and those easy breezy meal delivery services turn out not to be so easy breezy. But is there also a link between food allergies and weight gain? As with so many things, the answer is complicated.

People with food allergies have to avoid certain foods to prevent allergic reactions, and those dietary restrictions can have an impact on both nutritional balance and eating habits.

For instance, avoiding common allergens like dairy, nuts, or wheat could potentially lead to a reliance on less nutritious food alternatives, which might affect weight.

Food allergies also trigger an immune response that can cause inflammation in the body, and chronic inflammation has been associated with weight gain and obesity [1].

Then, there are the behavioural and psychological factors at play. Managing a food allergy or food sensitivity can be challenging and stressful, and that can lead to emotional eating, which can in turn lead to weight gain.

With that being said, it's not impossible to lose weight while dealing with a food allergy or intolerance. In this article, we'll break down everything you need to know about food allergies and weight gain.

Food allergies vs sensitivities: What's the difference?

On the surface, having a food intolerance and a food allergy may seem like similar conditions, as they both cause discomfort and require management.

However, they're actually distinct conditions with many differences [4][8].

There's also a common misconception that coeliac disease is an allergy or sensitivity to gluten or wheat, which is not the case. Rather, coeliac disease is an autoimmune disease in which the immune system will attack itself if gluten is ingested [2][7].

Food allergies

A food allergy involves the person's immune system, and when they eat a food that they're allergic to, they'll have an immune reaction [3].

An immune reaction is when a person's immune system mistakenly identifies a food as a threat and produces antibodies called Immunoglobulin E (IgE). Most commonly, people will have food allergies to peanuts, tree nuts, milk, eggs, wheat, soy, fish, and shellfish.

A food allergy can be severe or even life-threatening, and an allergic response can cause symptoms that range from mild — such as hives or itching — to severe, like anaphylactic shock [3].

These symptoms will usually appear quickly, often within minutes of consuming the offending foods.

Common symptoms of an allergic response include [5]:

• Hives
• Itching
• Swelling of the lips, face, tongue, or throat
• Difficulty breathing
• Abdominal pain
• Diarrhoea
• Vomiting
• Dizziness
• Anaphylactic shock

Management of a food allergy will look different for everyone, depending on the severity of allergy symptoms.

In general, strict avoidance of the allergenic food is advised, and if the severity of the allergy is life-threatening, it's important to have emergency medications, like epinephrine auto-injectors (EpiPens) on hand in case of accidental exposure [9].

Food sensitivities and intolerances

Unlike food allergies, food intolerance or sensitivity does not involve the body's immune system [8].

Rather, food intolerances are usually a result of the body's inability to properly digest or metabolise certain foods or food components.

Food intolerances are generally less severe than food allergies, but they still come with an array of uncomfortable or even debilitating symptoms.

Most commonly, food intolerances will present as bloating, gas, diarrhoea, constipation, abdominal pain, and nausea, and while delayed food allergies don't tend to appear, a food intolerance reaction can appear hours or even days after consuming the trouble food [6].

Common triggers for food sensitivities include lactose (in dairy products), gluten (in wheat and other grains), food additives (like artificial colours or preservatives), and certain natural substances (like histamines in aged cheeses).

Diagnosing food intolerances can be challenging, as it often requires removing foods from your diet for a few months under the supervision of a dietitian or health provider [9].

After the exclusion period, the aim is to gradually reintroduce different food groups back into your diet, to see which ones trigger a reaction. Once you've identified the trigger food or foods, management generally involves avoiding or reducing the intake of trouble foods.

Can allergies make you gain weight?

The good news is, food allergies and weight gain don't have to go hand-in-hand because allergies do not directly cause weight gain.

However, they can contribute to certain behaviours or conditions which can lead to weight gain.

Food allergies trigger your body's immune system, which causes inflammation. It's important to avoid allergent foods in order to help control inflammation, as chronic inflammation is linked to weight gain [1].

Having to navigate around food allergies can also be limiting, which can lead to an unbalanced diet and inadvertently cause weight gain.

Some medications, like antihistamines, can also have unwanted side effects which increase appetite and can indirectly cause weight gain.

Plus, there's the impact that the uncomfortable symptoms of food allergies or intolerances can have on a person's lifestyle. The stress and discomfort of managing them can make exercise more challenging, and it can be easy to fall into an unhealthy pattern of emotional eating. Both of these factors can lead to weight gain.

Finally, the symptoms of food allergies can cause sleep disturbances, and poor sleep is associated with weight gain due to hormonal changes that increase appetite and reduce energy expenditure.

Can sensitivities make you gain weight?

Food sensitivities and food intolerances can contribute to weight gain indirectly in several ways.

For starters, food intolerances often cause digestive symptoms like bloating and gas. These symptoms can cause abdominal distension, which could be mistaken for weight gain.

People with food intolerances often have to avoid certain foods to avoid flare-ups, which can mean replacing them with foods that are higher in calories and lower in nutrients.

An example of this would be someone with a lactose intolerance who might consume lactose-free products that are higher in sugar or fat.

While food sensitivities don't involve the immune system in the same way that food allergies do, they can still cause inflammation in the digestive tract, and as we've established, chronic inflammation is associated with weight gain [1].

Likewise, managing food intolerances can be stressful and uncomfortable, potentially leading to reduced physical activity and more emotional eating.

Frequently eating high-calorie comfort foods with excess sugar can lead to weight gain, particularly if you're not getting enough exercise.

Food sensitivities can also alter the composition of gut microbiota [10]. A healthy gut microbiome is crucial for proper digestion and metabolism, while imbalances in gut bacteria are linked to weight gain and obesity.

How to lose weight safely with food allergies

In order to lose weight safely while dealing with a food allergy or food intolerance, extra planning is required, but it's certainly not impossible.

Your best bet will be to work with an allergist or dietitian, who can help you create a safe eating plan that works around your allergens.

When you're headed out, it's also a good idea to plan your meals and snacks ahead of time, so that you know you'll have safe, healthy options available.

When grocery shopping, focus on whole, unprocessed foods as much as possible. This will help you avoid hidden allergens in packaged foods, and always make sure to read food labels carefully.

Whole foods are nutrient-dense, which will have the added bonus of keeping you full for longer, aiding in your weight loss journey.

It's also a good idea to be mindful of portion sizes, even with foods that won't trigger your immune system. After all, overeating can cause weight gain, even without a food allergy.

When it comes to weight loss, it's important to drink plenty of water throughout the day, get enough sleep, and engage in regular physical activity. These are crucial elements to support both weight loss and your overall health and well-being.

Keep track of your food intake, activity levels, and weight loss as you go. This will help you identify any patterns that appear and make adjustments to your routine as necessary.

If the prospect of losing weight while dealing with a food allergy or food intolerance feels overwhelming, or you just need some extra support, Juniper is here to help.

Juniper's Weight Reset Programme is all about setting you up for success — not just in the short-term, but for good. You can kickstart your weight loss journey with Wegovy or Mounjaro, two groundbreaking weight loss medications that work to control cravings, delay stomach emptying, and keep you feeling fuller for longer.

With any overeating tendencies under control, you're then free to work with your coach, who will provide you with advice and support, and hold you accountable along the way.

Our course levels are designed by physiotherapists
and dietitians to ensure that you don't gain weight back after you've hit your goal.

If you're ready to start your weight loss journey, check your eligibility today.

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