Be aware of the potential risks in VLCD dieting!

Although VLCDs demonstrably may have many potential benefits, they may result in a range of other less positive effects. Did you know that research has shown that sudden adult onset Calorie Restriction actually shortens the lifespans of mice? Though the lifespan enhancing effects of calorie restriction have been known since the 1930s, it was also known that if adult mice were suddenly put on a calorie restricted diet, their lifespans were actually shortened. However Dr. Walford  of the Calorie Resdtriction Society found (in the 1980s) that if mice were slowly transitioned from an ad lib to a calorie restricted diet, then their lifespans increased. The time for this transition recommended by Dr. Walford is a minimum of 6 to 9 months, but preferably 1 to 2 years. 

Here are some other possible negative effects of following a VLCD.

Appearance changes -- CR-induced weight loss can affect the appearance of those who pursue it. In the overweight, these changes may be perceived positively -- but in others, negative perceptions may arise. 

Bone health -- while evidence suggests that CR may support long-term skeletal health, weight loss is often accompanied by reduced bone mass. Work with your physician, especially an endocrinologist, to monitor your bone mass and markers of bone formation.

Cold sensitivity -- reduced body fat and decreased body temperature can make practitioners more sensitive to cold temperatures, while perhaps decreasing their sensitivity to extreme heat, and thus being a boon in summer.

Physical growth may be impaired by calorie restriction, as observed in lab animals. In addition, mental development and physical changes to the brain take place in late adolescence and early adulthood that could be negatively affected by calorie restriction. For this group, the best advice is to follow a normal (non-CR) diet until reaching early twenties.

Hunger (both psychological and physical effects), cravings, or food obsession -- thoughts about food sometimes increase while practicing CR. For some, this may interfere with other aspects of their life. On the other hand. Many people come to welcome hunger, knowing that the hunger hormones  ghrelin and orexin are good for the brain and the heart.

Menstrual irregularity -- dramatic weight loss can sometimes interfere with reproductive function in women. Women planning to get pregnant soon, should not begin CR until after having (and weaning) their baby.

Pregnancy -- low BMI is widely regarded as a risk factor in pregnancy. It can result in ovulatory dysfunction and thus infertility. Underweight mothers have higher levels of preterm delivery - and more low birth-weight infants. Women planning to get pregnant soon, should not begin CR until after having (and weaning) their baby.

Decreased testosterone Testosterone production often reduces at the beginning of CR practice. The beauty of the process is that the capability of producing this and other hormones is preserved, so as calorie restrictors age, they become more likely to have higher levels of many hormones than their peers. 

Rapid weight loss (greater than 1 - 2 lbs/wk) -- may do more harm than good, as noted in animal studies. Once your overall diet has improved, allow your body to take as long as it needs to reach your stable weight or calorie target.

If, for medical reasons, you are considering following a VLCD then I recommend that you take a look at the Calorie Reduction Socitey’s website which will help you choose the best foods to eat. You will see that it is in line with that which I have recommended people switch to, in order to facilitate weight loss and good health!  

Dr. Roy Walford, of the Calorie Reduction (CR) Society has written a book called  Beyond the 120 year Diet: How to Double Your Vital Years” and a book that he has written with his daughter Lisa, “the Anti-Aging Plan; Strategies and Recipes for Extending Your Healthy Years” -  these books also contain many recipes and tips for nutrition-dense, calorie-sparse meals.

The following nutritional summary  is taken from the CR society’s website in regards to how to go about calorie restricting your intake in a safe way. 

 

Replace calorie-dense foods with calorie-sparse, nutrient-dense foods - Before worrying about how many calories you're eating, make sure that the foods in your diet provide sufficient nutrition to avoid malnutrition once you begin to restrict them.

Avoid simple sugars and flours.

Sugars and flours generally contain very little nutrition for their calorie content. They also have high glycaemic indices, which means that your body absorbs them quickly, leaving you wanting more a short time later.

Eat both green leafy (salad) and other vegetables.

Vegetables -- both green leafy vegetables and non-leaf vegetables -- contain the highest content of a wide variety of nutrients for their calorie content. By volume (and often by calories), vegetables are the major component of many calorie restricted but not nutrient deficient diets.

Carefully select your protein and fat sources.

Both protein and fat are required macronutrients, but their form can have a significant influence on a person's risk factors for a wide variety of diseases – seeds and seed oils, nuts, fish especially oily fish, eggs and beans, pulses and legumes.

Make sure your protein intake is sufficient, but not overly abundant.

Common recommendations for total protein intake range from 0.6 to 0.8 grams per kilogram of body weight, and some recommendations are much higher. This is probably a minimum.

Make sure your proteins are complete and balanced.

A complete protein contains all the essential amino acids, while a balanced protein contains all those amino acids in ratios that are most useful to human biophysiology.

Most animal proteins are complete and well-balanced

There are very few perfectly balanced proteins in our food supply, but animal proteins tend to be among the most balanced. Unfortunately, animal proteins also tend to include undesirable components. For example, red meat is carcinogenic [PMID: 12376502], and meat (especially red meat) and dairy often contain large quantities of saturated fats. The nutrient density (as always, on a per-calorie basis) of meats is often lower than other choices.

Non-animal proteins can be balanced by combining different food families

One can get extremely detailed in finding "complementary" foods, but in general, combining legumes (beans) with grains will yield a balanced protein, and rice protein can complement the proteins in vegetables like broccoli, cauliflower, or spinach. Be aware, however, that both rice and grains (even whole grains) have relatively high glycemic indices and relatively low nutrient densities. If you're going to consume these, choose whole grains (not in the form of flours) and long grain brown rice.

Select monounsaturated fats, avoid saturated fats, and consume some Omega-3 fats

Foods containing monounsaturated fats include olive oil, almonds, hazelnuts, and avocados. Most of your fat intake should be from these foods. A very small amount of fat should be in the form of Omega-3 fatty acids, which are found in fatty fish (e.g. salmon) and flax oil. Caution: fatty foods, even healthy choices, are high in calories so be sure that you carefully track your intake so as to stay within your Calorie goal.