Fitness and nutrition news: week 36 of 2026

Week 36 of 2026 brings robust research on how diet and exercise influence metabolic health, body composition, and ageing. From the impact of a few seconds of sprinting to gut bacteria that protect muscle, through to the long-term effects of sweeteners, these seven news items offer practical, evidence-based insights for those looking to optimise performance and wellbeing.

Ketogenic diet reduced liver fat by 67 % in clinical trial

A clinical trial compared ketogenic, Mediterranean, and low-fat diets in people with obesity, prediabetes, and fatty liver. All three groups lost around 10 % of body weight, but the ketogenic diet reduced liver fat by 67 % versus 45 % for the other two. In addition, half of those who followed the ketogenic diet no longer met prediabetes criteria after four or five months.

Source: ScienceDaily — Fitness

Three minutes of sprints alter the blood more than 90 minutes of moderate exercise

Six 30-second sprints modified nearly a quarter of the blood proteins measured and more than 200 metabolites, while 90 minutes of moderate cycling produced much smaller immediate changes. Many of the proteins affected by sprints are associated with lower risk of obesity, type 2 diabetes, and other metabolic diseases. The findings suggest that high-intensity exercise may trigger unique physiological responses.

Source: ScienceDaily — Fitness

A gut bacterium helps maintain muscle strength with ageing

Scientists identified a bacterium, Roseburia inulinivorans, that is associated with greater muscle strength in humans and mice. Older adults who carried it had 29 % more grip strength, and treated mice gained nearly 30 % strength and developed larger, faster muscle fibres. The bacterium was less common in older people, and researchers see it as a probiotic candidate to combat sarcopenia.

Source: ScienceDaily — Fitness

Popular sweeteners may leave effects lasting for generations

Two widely used zero-calorie sweeteners, sucralose and stevia, altered the gut microbiome, reduced beneficial compounds produced by bacteria, and changed the activity of genes related to metabolism and inflammation in mice. Most striking: some of those changes were also detected in later generations that had never consumed the sweeteners. The authors urge caution with regular long-term use.

Source: ScienceDaily — Fitness

Exercise works better for maintaining weight than for losing it

Exercise alone is not the most powerful tool for losing weight, but it does appear to play a much larger role in preventing lost weight from returning. By preserving muscle, supporting metabolism, improving fat oxidation, and regulating appetite and blood glucose, regular physical activity facilitates long-term maintenance. The study reminds us that weight control is not only about cutting calories, but also about building sustainable habits.

Source: ScienceDaily — Fitness

An experimental compound helps burn fat without losing muscle

In mice, the compound TOFA increased energy expenditure by up to 18 %, reduced body fat without significant muscle loss, and improved blood glucose, triglycerides, and fatty liver. It also produced better results when combined with GLP-1 drugs such as Ozempic, Wegovy, Mounjaro, and Zepbound. Although it is a compound from decades ago, the results point to a new pathway for treating obesity by increasing expenditure rather than only suppressing appetite.

Source: ScienceDaily — Fitness

Each extra hour of prolonged sitting increases cancer death risk by 9 %

Sitting for long uninterrupted periods may carry greater health risks than sitting for the same amount of time in shorter bouts. Researchers found that each additional hour of prolonged sitting was associated with a 9 % higher risk of death from cancer. Breaking up sedentary time with light activity showed the opposite pattern, and replacing one hour of prolonged sitting with light activity was linked to a 12 % lower risk.

Source: ScienceDaily — Sports Medicine