Professor Franklin Joseph said it’s often why people struggle, even if they’re eating well and exercising
A weight loss doctor has warned that undiagnosed hormone imbalances could be stopping thousands of Brits from losing weight – even when they’re eating well and exercising regularly. From insulin resistance to cortisol spikes, Professor Franklin Joseph of Dr Frank’s Weight Loss Clinic says many people are fighting a biological uphill battle without knowing it – and no amount of calorie counting will fix the problem.
“We see patients every week who are doing everything ‘right’ but can’t shift the weight,” Prof Joseph explained. “In many cases, the issue isn’t food – it’s hormones.”
Why your body might be working against you
Hormones control everything from appetite and fat storage to energy and sleep. When they’re out of balance, Prof Joseph says weight loss becomes much harder – and sometimes impossible – without addressing the root cause.
“Insulin resistance is one of the most common roadblocks,” he said. “When your body becomes less sensitive to insulin, it stores more fat, particularly around the middle, and craves more sugar – even on a ‘clean’ diet.”
Another silent saboteur is cortisol – the stress hormone. While cortisol is essential in short bursts, chronic elevation can disrupt metabolism and lead to stubborn belly fat.
“Many people don’t realise that intense workouts like HIIT, especially when done too often or without recovery, can spike cortisol levels,” Prof Joseph added. “If you’re already stressed or underslept, it can backfire – leaving you exhausted, inflamed and no leaner.”
Why you can’t guess your way through a hormone issue
According to Prof Joseph, solving a hormonal weight loss issue isn’t as simple as cutting carbs or doubling down at the gym – and most people won’t find answers by guessing.
“You need to understand what your body is actually doing,” he explained. “We’re talking about things like insulin resistance, thyroid dysfunction, or stress hormones like cortisol being out of whack.”
These imbalances aren’t always picked up by standard check-ups – and can quietly stall fat loss, increase cravings and trigger exhaustion even with a so-called ‘perfect’ diet. While not everyone needs extensive testing, targeted checks for blood sugar, thyroid function or stress markers can help explain why someone isn’t seeing results.
“Sometimes it’s not about willpower – it’s about biology,” Prof Joseph said. “And the only way to know is to get properly assessed.”
How to know if hormones might be your issue
Telltale signs can include persistent belly fat, afternoon crashes, sugar cravings despite a high-protein diet, poor sleep, or fatigue that lingers even after rest days.
“If you’re following a plan and not getting results – don’t just push harder,” Prof Joseph said. “There could be something deeper going on.”
With rising rates of prediabetes, thyroid dysfunction and stress-related hormone imbalance, Prof Joseph urges people not to blame themselves for every stalled scale reading. “Sometimes your body isn’t being stubborn – it’s asking for help,” he said.