Low-Fat Foods Are Higher in Sugar


Many people believe that low-fat foods are generally higher in added sugar than the original full-fat versions.

Although this is highly plausible, it has never been scientifically confirmed.

For this reason, a group of Californian scientists decided to systematically compare the sugar content of several common full-fat foods with their lower-fat alternatives.

Below is a detailed summary of their findings, recently published in Nutrition & Diabetes.



In the late 70’s, public health authorities started recommending reduced fat consumption.

In response to increased consumer demands, food producers started offering low-fat or fat-free versions of foods.

However, this may not have been a step in a healthier direction. First, fat may not be as unhealthy as it was made out to be.

Second, food producers may have intentionally increased the sugar content of some processed food products to make up for the lack of tastiness caused by reducing their fat content.

This may have adversely affected people’s health, since sugar promotes obesity and chronic disease

Article Reviewed

This article presents the results of a systematic comparison of the sugar content of full-fat and reduced-fat versions of common foods.

A systematic comparison of sugar content in low-fat vs regular versions of food.

Study Design

The purpose of this simple study was to compare the sugar content of common foods and their fat-reduced versions.

The selection of foods was based on a list of foods recommended by the US National Heart, Lung, and Blood Institute.

This was a list of high-calorie, high-fat foods along with “healthier”, low-fat alternatives. The nutrient content of these foods was obtained from the USDA Nutrient Database.

Finally, the researchers used statistics to compare the sugar content in 100 grams of the regular, low-fat and non-fat versions of the selected foods.

Bottom Line: This study compared the sugar content of the regular, low-fat and non-fat versions of several common foods.

Finding: Lower-Fat Means Higher-Sugar

The study found that low-fat versions of foods were, on average, higher in sugar.

Additionally, the study showed a significant difference in the sugar content of the regular and low/non-fat versions of the following food groups:

  • Dairy products.
  • Meat, fish and poultry.
  • Baked goods, including snacks and sweets.
  • Fats, oils and salad dressings.

The difference was usually small, as shown in the chart below. It shows the median sugar content (g) of the regular, low-fat (“light”) and non-fat versions of foods within the four food groups.

sugar content

Bottom Line: The study showed that full-fat versions of foods are lower in sugar than their low-fat or fat-free alternatives.


The results of this study were presented as a “short communication”, including minimal details on the study’s methods and results.

For this reason, it is difficult to assess the study’s limitations. However, a few potential shortfalls should be mentioned.

First, it compared the sugar content of a limited number of foods.

Second, when you remove fat from a food product, such as milk, the relative proportions of protein, carbs and sugar increase.

This may create a statistically significant difference in the sugar content of full-fat and lower-fat foods, even if they do not contain any added sugar.

Third, the USDA Nutrient Database does not distinguish between added sugar and sugar that’s naturally present in whole foods.

The researchers did not address these potential limitations.

Bottom Line: This study had a few potential limitations. For example, it did not distinguish between added sugar and sugar that is naturally present in foods.

Summary and Real-Life Application

Gram for gram, there is no doubt that low-fat foods contain higher amounts of sugar than full-fat versions.

There are two possible reasons for this:

  1. The relative proportion of sugar increases when fat is removed.
  2. Food producers add more sugar to low-fat and fat-free products.

The present study does not distinguish between these two possibilities.

Whether people should chose full-fat or low-fat versions of foods depends entirely on their nutrient composition.

For example, choosing a low-fat food product may be good if it means that you are getting more protein without a large increase in sugar.

On the other hand, if it means that you’re getting a lot more sugar, then it is probably healthier to stick to the regular, full-fat version.

Written by Aline Pilani

Hey, I’m Aline Pilani. I am a certified personal trainer and nutritionist. I have spent the last 10 years of my life helping people losing weight, increase their health and confidence, and I truly want to do the same for you.