He reveals his distress when he can't have his favourite breakfast, which includes steel-cut organic oats and poached eggs.

But, what are these "steel-cut" oats that Carr so fondly speaks of?

We asked dietitian Dr Joanna McMillan to please explain. She also deconstructs Carr's day on a plate.

"Steel-cut oats are less common in Australia than rolled oats, but are more widely used in the US and in Scotland," she says.

"Rather than steaming and rolling the grain as is done to make rolled oats, the whole grain is chopped or sliced.

"When you cook steel-cut oats, the result is a more robust, nuttier porridge and tastes quite different to rolled oats. (My Scottish mother would only ever make porridge with steel-cut oats!)

"Oats make for a great start to the day, being rich in fibre, especially soluble fibre that boosts the growth of good bacteria in your gut and helps to reduce LDL-cholesterol levels in your blood.

"The antioxidants in oats have also been shown to help reduce the risk of cardiovascular disease. The berries Bob has with his oats add more antioxidants, including vitamin C.

"I'm assuming he eats his poached eggs separately. They boost the protein content of his breakfast, while adding a host of nutrients found in the yolk including a few omega-3 fats and carotenoids associated with good eye health.

"All up, it's a pretty sound, nutrient-dense breakfast. His fish dinner provides protein, but it does sound rather boring. But from a nutritional perspective that's fine so long as he adds a whole host of veggies to go with it.

"We need a minimum of five serves of veggies a day and a broad array of different types to gain all the plant compounds we need for optimal health. He doesn't mention lunch but I hope he is not going all day with nothing.

"A nutritious lunch, including a protein-rich food and a low GI fibre-rich carb, can help to prevent loss of muscle as we age, control your appetite through the day while keeping energy levels and concentration up through the afternoon."