For most people, 'weight loss' is an inaccurate term. While the goal is to see the needle on the scales creep down, it's a safe bet that fat loss, rather than the loss of lean muscle is what the dieter is aiming for. In fact, loss of lean body mass is a big problem for many people during a cutting cycle. One way to prevent the loss of muscle is to keep the body amply supplied with protein.
Protein has been shown to be more and more important for weight loss. A high protein diet has been shown to curb the appetite and have positive effects on the metabolism.
It's safe to say that lots of people are using protein to help achieve their weight loss goals. For those dieters, weight loss protein can be invaluable.
Weight loss protein consists of a very lean, low fat, low carb protein source, supplemented with ingredients that assist with weight loss. These ingredients fall into number of categories, including those that increase the metabolic rate and overall basal energy expenditure, increase the proportional metabolism of fat, block the absorption of fat or carbohydrates, anticatabolic substances that prevent muscle breakdown, ingredients that stimulate hormone production and even diuretics (1).
Weight loss protein is, in general, a very safe supplement, and appropriate for almost anyone to take. There is a lot of variety in ingredients within this class of protein, and as such, there is also a great deal of variety in the side effects that weight loss proteins have the potential to generate. Let's take a look at some of the effects that the more common ingredients in these products can have.
Weight Loss Protein Side Effects - Dairy protein
The majority of weight loss proteins are based on a blend of whey protein, most commonly incorporating both whey isolate and concentrate, and they sometimes contain slow digesting casein to increase satiety and control appetite. Dairy protein is a benign part of many people's diets, and the side effects are mild, the most common being bloating and indigestion, which can be remedied in many cases by substituting few large servings with multiple small servings. Lactose intolerant people may also wish to avoid whey concentrate and casein, as these may be sufficiently high in lactose to cause painful and unpleasant digestive symptoms. Acne is a less common side effects of dairy protein that can develop in some people (2).
Myths abound regarding the propensity of high protein diets to cause kidney and liver disease.
This has been studied in some depth, and even very high levels of protein supplementation have shown no impact on kidney function in healthy people (3). Similarly, protein supplementation is safe for the liver, even in high amounts.
Weight Loss Protein Side Effects - Caffeine and Catechins
In addition to being the world's favourite pick-me-up, caffeine, and catechins, which are molecules similar to caffeine that are found in tea, have shown some real positive results in weight control. These substances have a number of benefits, including appetite suppression, fat oxidation, and increasing metabolism, but they also have a number of side effects. The most obvious of these relate to the stimulant effect of these substances, and can include restlessness, fast heart rate and difficulty sleeping. Users of caffeine may also experience nausea, digestive problems, and frequent urination. Caffeine overdose can lead to tremors, seizure, and death, although a very large amount of the substance is required to elicit these symptoms. Symptoms can generally be alleviated by decreasing the dose (4). Some ingredients containing these substances include coffee extract, green tea extract and theobromine.
Weight Loss Protein Side Effects - L-Carnitine
The main role of carnitine in weight loss is to transport fatty acids into the mitochondria of the cell where they are burned to supply energy. This amino acid is naturally produced in the kidneys and liver and eaten in the diet, yet carnitine supplementation can have side effects for some people. Thankfully these are mild, and include stomach cramps, diarrhoea and nausea, and some people notice a fishy body odour. These side effects are dose dependent, and it would be very rare to experience any of these at normal therapeutic doses. People with kidney disease or epilepsy must consult a doctor before taking carnitine supplements because they can interfere with the medication.
Weight Loss Protein Side Effects - Conjugated Linoleic Acid (CLA)
This healthy fat is said to help weight loss while preserving muscle tissue, in addition to improving the blood lipid profile, increasing insulin sensitivity, and exerting anti-inflammatory effects. This fat is naturally occurring, and is eaten in foods such as meat and dairy, but may still cause side effects. The most commonly reported of these are digestive issues such as stomach cramps and diarrhoea. These is some research indicating that CLA may reduce the body's sensitivity to insulin (5). While other studies have refuted this finding, it is sensible for anyone suffering from a diabetic condition to consult their doctor before using CLA.
Weight Loss Protein Side Effects - Hydroxy Citric Acid (HCA)
This citric acid derivaive is present naturally in the rind of a number of tropical fruits, including Tamarind and Garcinia Cambogia, of thich it is the active ingredient. HCA is an appetite suppressant that stimulates the release of serotonin in the brain. It is also thought to block carbohydrate absorption by the body. It has been used as an ingredient in food throughout Asia for many years, and is considered to be extremely safe. Side effects are rare and mild, and may include nausea, stomach upset and headache (6).
Weight Loss Protein Side Effects - L-Tyrosine
This amino acid is a common inclusion in weight loss proteins because it is a precursor to a number of important hormones and neurotransmitters, including serotonin, which can lift mood and supress appetite, melotonin, which is responsible for regulating the body clock - disturbances have been shown to trigger unhealthy food cravings, and thyroxin, which is the thyroid hormone, responsible for regulation of metabolism. In addition, tyrosine dipeptide has been discovered to act as a satiety signal within the body. Tyrosine is a natural component of protein, and we eat it in food. It is a very safe supplement, and side effects are mild and uncommon. These can include diarrhoea and stomach upset, and insomnia is sometimes reported by those taking higher doses, thought due to enhanced dopamine production. For these people, tyrosine is best avoided at night (7).
These are some of the more common ingredients in weight loss protein, but this is a large and diverse category of products that use many ingredients. Although these are generally safe and well received, it is advisable to do some research into these before using a weight loss protein, and to consult a doctor about any concerns, particularly for people with pre-existing medical conditions.
(1) Jeukendrup AE, Randell R. Fat burners: nutrition supplements that increase fat metabolism. Obes Rev. 2011 Oct;12(10):841-51.
(2) Simonart T. 'Acne and whey protein supplementation among bodybuilders.' Dermatology. 2012;225(3):256-8.
(3) Poortmans, J.R. and Dellalieux O. (2000) Do regular high protein diets have potential health risks on kidney function in athletes? International Journal of Sport Nutrition & Exercise Metabolism 10, 28-38.
(4) Hursel R, Westerterp-Plantenga MS. Catechin- and caffeine-rich teas for control of body weight in humans. Am J Clin Nutr. 2013 Dec;98(6 Suppl):1682S-1693S.
(5) Gaullier JM, Halse J, Høye K, Kristiansen K, Fagertun H, Vik H, Gudmundsen O. 'Supplementation with conjugated linoleic acid for 24 months is well tolerated by and reduces body fat mass in healthy, overweight humans.' J Nutr. 2005 Apr;135(4):778-84.
(6) Ohia SE, Opere CA, LeDay AM, Bagchi M, Bagchi D, Stohs SJ. Safety and mechanism of appetite suppression by a novel hydroxycitric acid extract (HCA-SX). Mol Cell Biochem. 2002 Sep;238(1-2):89-103.
(7) L-tyrosine. Monograph. Alternative Medicine Review. 2007;12(4):364-368.