The surprising reason a sugar-free diet may backfire

A new study claims that, contrary to the long-standing belief that sugar-free diets are beneficial, they may be counterproductive. “Mice on a sucrose-free low-fat diet showed worse blood sugar control, increased inflammation, disrupted gut bacteria, and signs of fatty liver compared with mice that consumed some sucrose,” the study presented at the Endocrine Society’s annual meeting in Chicago stated in a press statement on its website.

The study further noted that completely removing sugar from the diet could have unintended effects on gut and metabolic health. The group of researchers from the Dasman Diabetes Institute in Kuwait compared a low-fat diet fed to mice without sucrose with one containing sucrose over 16 weeks.

DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.

The study read, “Despite maintaining similar body weights, mice on the sucrose-free diet experienced several negative health changes compared with the control group. These included poorer glucose control, insulin resistance, imbalances in gut microbes, intestinal inflammation, and changes associated with fatty liver disease.”

The researchers noted that not much was previously known about the “potential consequences of highly restrictive low-fat diets that eliminate sugar”.

Dr Pranav Ghody, consultant endocrinologist and diabetologist at Wockhardt Hospitals, Mumbai Central, called the findings “interesting” but cautioned that they should be interpreted with caution. “This study involved mice. While animal studies can provide useful insights, their results do not always apply to humans. The research highlights that nutrition is rarely about cutting out a single ingredient entirely. The overall quality and balance of the diet matter much more than extreme restrictions,” said Dr Ghody.

Does this mean a sugar-free diet is unhealthy?

Not necessarily, clarified Dr Ghody. “There is a key difference between eliminating added sugars and removing all sugars. Cutting back on added sugars from sweets, sugary drinks, and ultra-processed foods benefits most people. However, carbohydrates and naturally occurring sugars found in fruits, vegetables, dairy products, and whole grains are vital sources of energy and nutrients. A completely restrictive approach may not be the best choice,” said Dr Ghody.

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What should you consider (Photo: Freepik)

Why might eliminating sugar affect gut health?

The gut microbiome thrives on a variety of foods. “Many foods with natural sugars also offer fibre, vitamins, minerals, and compounds that support beneficial gut bacteria. If a sugar-free diet becomes overly restrictive and excludes a wide range of healthy foods, it could disrupt the balance of the gut microbiome. However, more research on humans is needed before making firm conclusions,” said Dr Ghody.

The study also reported insulin resistance and poorer glucose control in mice. Is that surprising?

Dr Ghody noted that it is a “bit unexpected” because cutting back on sugar is often associated with improved metabolic health. “However, metabolism is complex. The body responds not only to how much sugar is consumed but also to the overall makeup of the diet, including fibre, protein, fats, and other carbohydrates. This study reinforces the idea that dietary patterns matter more than focusing on a single nutrient.”

What is the takeaway for people trying to improve their health or manage diabetes?

The goal should not be to fear sugar or cut out entire food groups. “Instead, people should aim to reduce added sugars while keeping a balanced diet rich in vegetables, fruits, whole grains, lean proteins, healthy fats, and enough fibre. Sustainable eating habits are usually more effective for long-term metabolic health than very restrictive diets,” elucidated Dr Ghody.

What is the biggest misconception about sugar?

One common misconception is that all sugars are equally harmful. “The body processes sugars differently depending on the food source. An apple, for instance, comes with fibre, antioxidants, and nutrients. In contrast, a sugary soft drink offers calories with little nutritional value. The focus should be on overall dietary patterns rather than viewing sugar as the sole factor in health.”

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DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.