Do Processed Foods Increase Fat Gain? - Coach Mark Carroll


Aug 19, 2022
Sheridan Skye

Though “if it fits your macros” (IIFYM) has grown in popularity in recent years, there is still a lot of confusion about what the term actually means. IIFYM stands for “if it fits your macros” and refers to a style of eating that emphasises macronutrients (protein, fat, and carbs) rather than specific foods. The idea behind IIFYM is that you can eat whatever foods you want as long as you hit your nutrient goals for the day. This approach can be helpful for people who have trouble sticking to traditional diets, as it offers more flexibility and allows you to enjoy your favourite foods without feeling guilty. However, IIFYM is not a free pass to eat whatever you want, whenever you want (at least, that’s not how Mark or I recommend following IIFYM). To reap the benefits of this eating style, you need to ensure that you’re getting adequate nutrients from nutrient-dense foods. 

Key terms:

Since we will be discussing the role a processed food diet has on fat accumulation, instead of words like health, wholefoods and processed foods, I will be using words such as: 

  • Nutrient-dense, low-energy foods and 
  • Energy-dense, low nutrient foods 


People often think of ‘bad’ foods when they hear the word ‘processed’, and I take issue with this for a few reasons.

Reason #1: Food holds no morals, only the morals you place on it. 

There’s no such thing as a universal’ bad’ food for everyone. Sure, some foods may not be the best choice for someone trying to lose weight or lower their cholesterol, but that doesn’t mean that those same foods can’t be enjoyed in moderation as part of a healthy, balanced diet. So next time you feel guilty about indulging in your favourite treat, remember that it’s OK to enjoy all kinds of food. 

Reason #2: “Health” is a subjective experience. 

When it comes to health, there is no one-size-fits-all approach. What works for one person may not work for another, and what is healthy for one person may not be healthy for another. This is because our bodies are unique, and we each have different genetic makeups, lifestyles, and medical histories. As a result, what is healthy for one person may not be healthy for another. 

Reason #3: Not all processed foods are ‘bad’, and some even benefit us. 

Processed foods are foods that have been altered from their natural state, usually by being packaged, canned, or frozen. People often assume processed food refers to confectionary foods like chocolate, ice cream and lollies. Still, foods such as oats, weetbix, and wholegrain bread are processed and provide us with energy, vitamins and fibre.

Now that we have that covered let’s dig into the study.

This study put males and females without any current medical conditions in a research building for one month and had them consume an ultra-processed diet for two weeks, followed by an unprocessed diet for two weeks. For the purposes of this study, ultra-processed referred to foods such as turkey bacon and bagels with cream cheese, and an unprocessed diet referred to foods such as walnuts, skim milk, bananas and oats. Participants could eat ad libitum, which means as much or as little as they pleased. The researchers found that the ultra-processed food group ate more food during meals and consumed more snacks throughout the day than the unprocessed food groups

So yes, an ultra-processed food diet may lead to fat accumulation compared to an unprocessed diet. 

What is really cool about this study is that both the ultra=processed food diet and the unprocessed food diet contained the same amount of protein, carbohydrates and fats! This is super important because it means that an argument can’t be made that there were other factors such as a decrease in satiation if the protein content of the meals were lower in the ultra-processed food diet. 

So one has to ask themselves, does an ultra-processed food diet directly lead to fat gain or is it simply easier to overconsume calories on an ultra-processed diet? 

And the answer is: that it is easier to overconsume an ultra-processed food diet and, therefore, put yourself in a calorie surplus. This means that an ultra-processed food diet doesn’t directly lead to fat gain. Still, indirectly, it is harder to reach satiation, so you will likely overeat. 

Other considerations

  • An ultra-processed food diet is energy dense and nutrient-low, which may increase the risk of developing micronutrient deficiencies. 
  • An ultra-processed food diet lacks fibre essential for satiety, gut health and cardiovascular health. 
  • Consuming an ultra-processed diet requires you to use more willpower to avoid overeating. 

Practical takeaways

Flexible dieting is a great way to achieve your health and fitness goals. Still, it is essential to be mindful that consuming a nutrient-dense, energy-low eating style improves adherence, satiety and overall health. 

Yours in Health, 

Sheridan Skye.