How to lose weight by eating fat and being full

Raised in Hampstead, where her parents still live, she trained as a junior doctor at the Royal Free.

"Is Friday still Ham&High day?" asks Dr Hameed, now a consultant endocrinologist specialising in obesity medicine at St Mary's Hospital in Paddington.

Working with patients in preparation for gastric band or other weight loss surgery, she hosts bi-weekly video discussions with slide shows and a daily motivational email to help them lose weight before the procedure.

And she has just published The Full Diet: The revolutionary new way to achieve lasting weight loss (Michael Joseph, £14.99).

Looking at her slim frame which belies her 43 years and four children, I ask: "why obesity?"

She says that her fascination sprang from being supported for her PhD in endocrinology by Professor Sir Steve Bloom of Imperial College.

"He's the pioneer of studying the hormones that talk between the gut and the brain – hormones like ghrelin which control our hunger levels. That's the science that lit the touch paper for the book."

When I say it seems we are controlled by hormones, she agrees.

"We are. Our feelings, our energy, our mood, our growth, bone health or heart health. One of the key aims of my book is that it shouldn't be a secret, it shouldn't just be in journals, behind paywalls or at specialist conferences."

In one chapter she asserts that "If you put on weight that means you are a survivor" - a much more positive way of looking at fat.

"For all of human history it's been a great advantage. Your genes meant you survived, which meant you reproduced and passed your genes on. You'd done your life's work. It's only recently that these genes have become a disadvantage because we never had this overabundance of food and this particular food which our biology cannot manage," she says.

Foraged berries can be made into several dishes (Image: Kerstin Rodgers)

The weekend before, she had been on call in the emergency department at St Mary's.

"I would say, back of the envelope calculation, probably a third of the people who came in had diabetes, type two. If you have pneumonia (or any other medical problem) your blood sugar will go up. Today, in terms of patient care, it's safer to presume somebody has diabetes."

While there is blame and stigma attached to diabetic patients, she says "70 percent of your tendency to be diabetic, even type 2, is genetic. We know that berating people and telling them off doesn't work. When you meet people and hear their stories, there's so much blame, so much loss of self esteem, notions of the deserving and the undeserving ill."

Gary Sycamore's trug of vegetables Highgate Horticultural Soc Autumn show. Picture: Nigel Sutton (Image: © Nigel Sutton)

The book's title refers to a diet where you will feel full and are allowed to eat fat. Previously demonised, fat doesn't make you obese but promotes satiety, the feeling of being full. The book lays out some basic rules:

The black bag: put all the carbs, sugar, diet and junk food into a black bag and chuck it.

Tune in to your gut: to your hunger 'ghrelin' signals. Eat when you are hungry and stop when you are full.

Eat no or low carbs, high protein, good fats (butter and olive oil), full fat dairy, no sugar. The Michael Pollan dictat of "only eat things your grandmother would recognise as food". No ultra processed food. No artificial sweeteners. Avoid alcohol (it's basically sugar).

Have an "eating window" of eight hours and close it for 16. For example: if you have a late breakfast at 11am, you must have finished dinner by 7pm. Then your digestive system can rest.

Batch cook to help you control yourself throughout the week. Have a personal bento box with healthy meals and snacks. This will not only save money at work but also minimise temptation to eat junk.

Eat the rainbow: feed your gut microbiome by eating a variety of foods, of different colours, high fibre and fermented foods. "Have vegetables at every eating opportunity, even breakfast."

High fibre: read labels to see how much fibre is in what you are eating. We should be eating 30g of fibre (inulin) a day. This is more difficult than it sounds, for instance, 200g of Brussels sprouts is 10g of fibre. Two teaspoons of linseeds contains 1.4g of fibre. "For many people their fibre intake could be close to zero," she warns.

Other rules include avoiding smoothies as these are effectively "sugar solutions," go for fruit rather than fruit juice because it contains fibre. Choose low sugar fruit such as berries rather than pineapples and mangos. In terms of sugar, it makes no difference if it comes from honey, maple syrup or coconuts, it's all sugar. Avoid.

"Even if I worked seven days a week, I couldn't see enough people to change their lifestyle," explains Dr Hameed.

"This book will spread my methods to a wider audience. I like eating.' I hope it comes across in the book that food should be delicious and joyful."

Dr Saira Hameed has published The Full Diet (Michael Joseph £14.99) She is a consultant endocrinologist at St Mary's Paddington and a senior lecturer in diabetes, endocrinology and metabolism. (Image: Kerstin Rodgers)