The media keeps simplifying this diet as “soups and shakes”, so I can see why some people may be outraged. But it’s much more than that. These meal replacements (MR) are used to help obese patients meet a target of 800 calories per day. Otherwise termed: very low calorie diet (VLCD).
The VLCD is used to get obese patients into a state of ketosis (keto). Ketosis is when the body runs out of glycogen (stored sugar) and starts to use ketones (from fatty acids). Put simply, this means that stored fat is utilised for energy instead of glycogen stores. Cue rapid weight loss.
Yes, keto is the diet that healthcare professionals usually slate. This is because for the general population, this diet is not optimal. So before you throw out your loaf of bread, here’s why not. The keto diet:
Is low in carbs and fibre. As in the UK our main contributor of fibre is cereals and cereal-based products which are not allowed on keto. This could put us at risk of disease, and reduce our bowel health and function.
May lead to nutrient deficiencies, particularly in selenium, certain B vitamins and magnesium.
Is high in dietary fat intake, particularly from trans and saturated fat. These types of fat are related to increases in inflammation within the body.
Is too restrictive. They may mean you miss out on social events or time with loved ones. You may even find you stopped getting invited to things. No one likes the food police.
But clinically, ketosis can help manage certain health conditions. For the purpose of this article, it’s particularly useful for helping obese patients lose 5-10% of weight loss which can have benefits such as:
Improving heart health, due to improvements in blood cholesterol, blood lipids, blood pressure and inflammation.
Improved mental health
Improved sleep apnoea and breathing
Improved mobility and pain
Improved fertility (men too!)
Reduced risk of certain cancers
More recently, short term VLCDs have been used in obesity and type 2 diabetes (T2DM) to get patients into ketosis. Clinical trials on obese patients show that VLCDs (~8-20 weeks duration) using total meal replacements (TMR) can produce significant weight loss and remission of T2DM. With over 30% remaining in remission at 2 year follow up - which is significant.
So why TMR?
MRs are fortified with vitamins and minerals to prevent deficiency (which can occur on other low calorie diets). Plus they contain plenty of protein. This protects muscle mass; preserving immune function and metabolism. So they are much safer to follow, compared to fad diets.
Patients may get up to 5 MRs (bars, porridge, curries, pancakes etc) a day. Which means if spaced out, patients can eat at regular intervals throughout the day. Unlike some other fad diets 👀
MRs take the maths out of dieting. This prevents calorie counting (snooze), food weighing (who actually has the time?) and removes some thought processes around food (which can make dieting mentally draining).
Why a multidisciplinary approach?
The dietitian screens patient prior to commencing a programme with VLCD or not, to ensure they are eligible. Screening includes:
disordered behaviours (eating, drugs, alcohol)
medical history (gallstones, kidney disease, cancer, stroke)
medication history (steroids, SSRI etc)
supports behaviour change during TMR and any side effects
provides dietary advice for slow reintroduction and maintenance.
The doctor will examine medical history, examine blood results, adjust medications and support the wider team. The psychologist will support behaviour change in the patient, facilitates education around body image and disordered eating, works with the patient to develop coping strategies and supports the wider team with complex caseload.
This is a promising option for obese patients and those living with T2DM. Weight loss is the by product of this diet, with main benefits on the slides. This diet should only be carried out under the clinical supervision of doctors, psychologists and specialist dietitians.