Part of the difficulty in maintaining such extreme calorie restriction may lie in food choice and portion control. There is a challenge in eating enough of the correct foods to consume enough nutrients and remain full enough to avoid straying from the diet.

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Total diet replacement plans remove the element of choice for patients, making a diet easier to follow and increasing the chance that patients will stick with it.

The NHS soup and shake diet involves following a calorie restricted diet (800-900 kcal) of low calorie, nutritionally complete, total diet replacement products – made up, as the name suggests, of soups, shakes and bars – before reintroducing other foods, bridging progression onto a healthy maintenance diet, supported by coaches for 12 months.

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The results confirmed that total diet replacement plans can induce weight loss as well as a decrease in HbA1c. In some patients this was enough to induce diabetes remission. Great news indeed.

However, this is only one piece in a more complicated jigsaw puzzle. Not everyone who follows the plan will be able to reverse their diabetes. For example, even though the soup and shake diet restricts patient food choice as well as calories, sticking to a liquid only plan can still be difficult for some.