For those unfamiliar with Princess Grace Kelly of Monaco, allow me to fill you in. The radiant actress rose to fame in the 1950s with the American Western, High Noon. Perhaps most iconic was her marriage to Prince Rainier III in 1956, by which she became a real life princess. Alongside this regal status, she was also an enviable style icon, with many yearning for her elegant, dancerly figure. While she remained shy about disclosing her measurements, her meal plan was no secret, and I decided to put the charming blonde's diet to the test, learning some vintage health tips along the way...

1) Fill up on oatmeal.

Eliane Lindeque

Grace would swear by her morning oatmeal to kickstart her day and help curb later cravings. Oatmeal is not only nutritious, it keeps you feeling fuller for longer, giving you the energy you need to get through until noon. As someone who tends to drown their morning cereal in soya milk, I found my oatmeal breakfast dense and hard to get through, but it definitely filled me up and I'm beginning to realise why it's such a popular choice. I didn't find myself reaching for any sugary snacks immediately after and felt satiated with one serving.

2) Snack before 11am.

Rebecca Salter

While it was difficult to find an exact timing for Grace's morning meal, she was known to bring emergency snacks on set in case cravings kicked in before lunch. Considering the heaviness of that morning oatmeal, I would have to guess her breakfast was pretty early and that her snacks were 'filler' foods before her midday meal. Following Grace's advice, I kept a selection of her favourites on hand—carrot sticks, celery sticks, and dried apricots.

3) Stick to whole grains.

Rebecca Salter

Grace strictly avoided sugar, along with white bread and rice—most likely a tip she learnt from nutritionist Gayelord Hauser—opting instead for wholegrain whenever she could. It was hard to pinpoint a specific lunch plan, so I settled on a salad sandwich with wholegrain bread. During her three-month detoxes, and following Hauser's advice, Grace would stick to raw food salads for her midday meal. I definitely benefitted from combining two of Grace's top tips—the wholegrain helped me to feel satisfied and the salad provided some well-needed greens after a satiating but fruit-free breakfast.

4) Drink plenty of water.

Eliane Lindeque

Grace seemed to favour three drinks throughout her stardom—water, skimmed milk, and green tea (often with a teaspoon of honey). She removed alcohol from her diet and kept hydrated with enough H2O and high-water-content fruits. During her detoxes she would load up on apples and oranges for vitamin intake and hydration. As Gordon Ramsay's recent diet hack reveals, water helps keep you satiated for longer and prevents overeating. I've never been one to find fruit 'filling', but my apple intake did help to keep me alert and scored me some extra nutrition points.

5) Keep meals light.

Rebecca Salter

As her name suggests, Grace was not the type to binge on an extra large pizza—although sources suggest she did enjoy the occasional burger. Rather, she kept her meals light and small-portioned. As she told one reporter, 'I do enjoy good food but try to eat correctly, the right things'. Grace ate fish and meat only rarely, with most of her diet consisting of whole grains and vegetables. As tempted as I was to test out a baked salmon recipe, I wanted to try a meal more in line with Grace's regular option. I thought the modern trend for Buddha bowls would be a perfect update on her strict dietary plan. I paired wholegrain rice with broccoli (Grace enjoyed a more elaborate broccoli soufflé) along with some carrots and salad leaves, resulting in a well-balanced and satisfying meal, even if the lack of fattening dressings made it a little dry.

6) Say no to dessert.

Eliane Lindeque

This firm and inflexible diet tip made me realise Grace's meal plan would be less indulgent than Marilyn Monroe's. While Grace's biographer recalls her occasional indulgence in tea and cookies, she was, for the most part, adamantly opposed to dessert's temptations. I rewarded my 'Grace day' instead with a warming cup of green tea, with that teaspoon of honey as sweet as I'd get for my post-dinner treat.

Grace clearly cared for her figure in the dedicated fashion common to many Hollywood stars both then and now. At the same time, Grace seemed to be incredibly mindful about food, rejecting the idea of fad diets and choosing a sensible, though sometimes rigid, approach to her meals. While I found the persistence of wholegrain foods a little tedious, I did enjoy trialling Grace's favourite snacks (because who doesn't love yoghurt with berries?). I'm not sure I would opt for one of her fruit-based detoxes, but her filling breakfasts and sensible snack choices are definitely snippets of wisdom. And with green tea increasingly recommend by experts as a pre-slumber beverage, I think the bygone princess was certainly on to something.