Dietitian says low fat diets have ‘done a lot of damage’
Dr Trudi Deakin’s feelings towards fat are the opposite of what they were when she qualified as a dietitian more than 25 years ago.
She describes her former self as “a fat-phobic dietitian,” telling me “my family laugh that I now eat butter and I never used to.”
If you, like me, grew up in the era of calorie counting, being bombarded by low fat supermarket foods and a tangible fear around the idea of eating saturated fats (like real butter, cheese and meats), then you’ll understand why Trudi’s u-turn on fats has gained attention.
“I think when you start to deliver information that doesn't tie in totally with the dietary guidelines, then people start to pick up on it,” she told me.
Current NHS eating recommendations for a healthy lifestyle suggest we should opt for ‘unsaturated oils and spreads.’
But as the chief executive of X-PERT Health - a charity that trains people in making dietary and lifestyle changes based on evidence-based information to help prevent and manage type 2 diabetes, obesity and metabolic syndrome, Trudi insists one diet can’t work for everyone.
“We offer dietary flexibility, so we don't say ‘one-size-fits-all - everyone has to follow a low fat diet,’ she told me in healthHackers® episode 35, we say: ‘there are different dietary approaches and different things work for different individuals.’”
According to Trudi, two-thirds of the population are overweight, so for that section of society, “it's likely that they've got insulin resistance.”
Insulin resistance and metabolic syndrome can develop into type 2 diabetes. See healthHackers® episode 35 to hear Trudi outline the signs that suggest you could be at risk.
Her charity, which has partnered with a number of NHS trusts, offers structured programs that have educated more than 250,000 people at risk of, or living with, type 2 diabetes on losing weight and improving their blood glucose readings.
“We talk about glycemic index, glycemic load, the amount of carbohydrate being the most important factor [as opposed to a conventional focus on sugar in the diet].
Trudi’s most controversial message, however, is her one around fats.
“…fats aren't bad for us. Fats are essential to life.”
Eat fat to lose fat
“I think it's generally accepted now that diabetes is a carbohydrate intolerant condition, especially Type 2 diabetes and pre-diabetes. But if people reduce their carbohydrate intake to their tolerant level - so they can meet their blood glucose levels/targets… then they tend to need to replace it with something,” Trudi told me.
If a person cuts carbs but doesn’t replace it with something else (like ‘good’ fats) -they’ll still feel hungry, and then the diet isn’t sustainable, she explained.
“A low carbohydrate diet is a moderate protein diet… it's not a high protein diet, so people need to fuel off fat. That fat is either dietary fat or stored fat in their body and it normally is a combination of the two.
“We encourage people to eat fat to satiety… to true physiological fullness and not emotional fullness,” she said.
Listen to healthHackers® episode 36 to hear Trudi breakdown dietary fats: which ones to eat, cook with and avoid.
Her opinions are based on changing research over time.
“They say that half of what you learnt at university is incorrect, but at that time, you don't know which half is incorrect. That's certainly true with saturated fat and myself.
If you’re reading this with alarm bells going off in your head about fats increasing the risk of heart attacks, Trudi also told me:
“Some of the saturated fats are harmful but they've been produced from the carbohydrate.
“When they have looked at a Cochrane systematic review… there was no evidence at all that dietary saturated fat increases the risk of cardiovascular disease. So that now should be put to bed.”
Won’t I get fat if I eat more fat?
‘That's a common myth,” she told me.
In fact, Trudi believes: “the low fat diet has done a lot of damage.”
She argues that since low fat eating became a dietary guideline in 1983, people have started to eat more frequently.
“My grandparents used to have three square meals a day. Now it's quite normal for people to eat at six or seven occasions a day, grazing throughout the day…that increases our insulin levels in our body.”
According to Trudi, that puts us into “fat storage mode” whereby we aren’t burning off the actual fat that we want to lose.
“It’s not just what we eat, it’s how frequently we eat.
“Two-thirds of the population are overweight. One in 4 adults are obese. That's quadrupled in the last few decades,” she told me.
‘Eat less, move more and get fat’
Trudi was one of the key speakers, with her presentation titled: ‘Eat less, move more, and get fat’ - about why people end up with weight-loss plateaus, feeling disappointed and bigger than they were before they started their diet.
The culprit, she argues, is the slowing down of basal metabolic rate, caused by cutting calories but snacking frequently on carbohydrates.
Make no mistake - you will likely lose weight initially, as Trudi said: “all diets are successful in the short term.”
However, she explained: “If people are eating frequently and they're basing their meals on carbohydrate, insulin levels are high.
“Insulin is an energy storage hormone, so if they're storing their energy and they have dropped their calories… what does the body do? It then compensates, conserve calories and slows down,” she told me.
As a result, weight loss stalls, a person wrongly feels it’s their fault, they also probably feel cold because their metabolic rate has dropped down, she explained.
“The person doesn't understand… so they go, “I've stopped losing weight. What's happened?”
“When the willpower breaks then they'll start consuming the foods that they’ve missed and so then they experience weight gain.”
How do we lose weight without slowing our metabolism?
Trudi told me: “The more that people can drive their insulin levels down, the more they can access their fat stores.”
Rather than obsessing over calories, it means eating carbohydrates “to tolerance.”
If you’re struggling with excess weight, have been told you have pre-diabetes or type 2 diabetes, Trudi said those all indicate you are eating carbs beyond your tolerance range.
We also make carbs within our bodies from proteins and fats.
“That's why carbohydrate isn't an essential nutrient because if we don't eat carbohydrate then we can make it,” she said.
Despite being a dietitian, Trudi doesn’t just focus on foods for health gains.
“Sleep deprivation, being chronically stressed, increases stress hormones such as cortisol,” she said.
Cortisol tells the body to release energy, like glucose, to cope with that stress.
“Even if people aren't consuming carbohydrate… if they're very stressed, they're not sleeping well, it could be as though they’re on a high carbohydrate diet,” she told me.
Nutrition can be a confusing world for ordinary people (me included). There’s a marked divide between dietary thought-leaders who oppose each others’ arguments. As a consumer, it can feel like every day there’s conflicting advice about what to eat and what not to eat.
I asked Trudi how she handles the sometimes disturbing discourse.
“We’ve got well over 100,000 people's results on our audit database and we can demonstrate that when people get the right education that's evidence-based and they make changes with their lifestyle, especially their diet, then it impacts on their clinical outcomes.
“They get reduced blood glucose levels, they lose weight, they keep it off, they get a reduced waist circumference.
As for arguments, “that’s a waste of energy.”