Slender Blend is a product from UK based company Protein World. This product claims that it can help you to lose weight and tone up. Protein World describes the product as a “high protein, low calorie meal replacement”. This review will examine the ingredients listed on the packaging and website for the product to understand if it can achieve the claims that have been put forward.

Whey Protein Concentrate

Whey protein helps aid muscle protein synthesis when combined with resistance training (1, 2). Other key features include increasing muscle mass (3), an increase in lean body mass (4) and greater recovery from exercise (5). Longer periods of supplementation have shown greater gains in fat free mass (6).

Muscle protein synthesis is increased due to high concentration of Leucine (BCAA) which is a signalling molecule needed to increase muscle protein synthesis (7). Consumption of whey protein helps increase muscle mass due to a greater amount of peripheral nitrogen retention whereas soy protein has been found to have a greater effect on splanchnic protein synthesis (8).

The reason for greater recovery of exercise can be due to a post exercise insulin response (9, 10) which means glycogen resynthesis occurs rapidly so exercise can be prolonged, with greater training volume increased hypertrophy and decreased muscle damage.

Guarana extract

A main ingredient of guarana is caffeine; there have been several studies that have shown a significant increase weight loss with caffeine (11), but there have been few studies that have looked at the nutritional supplement on weight loss. Other studies of guarana have shown an increase of energy expenditure and fat oxidation of short periods of time which suggest that this could be due to a reduction in respiratory quotient and an increase in lipid oxidation (12).

Green Tea Extract

Green tea supplementation has been shown to have several health properties including an increase in plasma antioxidant which will lead to a lowering of oxidative damage (13, 14), decreased blood pressure (15, 16) and it can protect against coronary atherosclerosis (17). Other health effects that green tea can have includes a lowering of cholesterol, an increase of insulin activity (18) and a regulation of blood glucose levels which can help reduce body fat.

Vitamin A (retinol acetate)

Vitamin A is a diverse vitamin that has a wide range of functions. Vision improvement is one positive aspect of vitamin A supplementation (19), Another is bone and body growth which can be improved (20). Immune function is boosted by an increase of white blood cells which can destroy harmful bacteria (21). Epithelial cells require Vitamin A in order to function properly, these cells serve as barriers to infection by bacteria and other sources (22).

Vitamin D3 (cholocalciferol)

Cholecalciferol is a form of Vitamin D and helps in the absorption of calcium in the stomach (29). Calcium is a vital part of dietary consumption in order to aid growth and maintenance of bones (23). Other important benefits of calcium include helping blood clotting (24), heart contractions (25), lungs (26) and muscles to function properly (27), this is due to calcium binding with phosphate to create calcium phosphate (28).

Vitamin E (d-alpha-tocopherol)

Dl-alpha tocopheryl acetate is otherwise known as vitamin E and is an antioxidant (30). This means that it protects the muscles from free radicals, which causes muscle soreness and damage to the muscle tissue and fat cells (31). Dl-alpha tocopheryl acetate can counteract these free radicals before damaging these parts of the body which can allow exercise to be prolonged (32).

Vitamin C (ascorbic acid)

Vitamin C is known to be a powerful antioxidant (33). Studies have suggested that it can increase endothelial nitric oxide by protecting it from oxidation and increase synthesis, another function that Vitamin C has suggested includes reducing blood pressure (34), however the only proven function of vitamin C is the prevention of scurvy (35).

Vitamin B1 (thiamine)

Thiamine is also known as vitamin B1 (36) and is essential in carbohydrate metabolism and oxidation (37). The reported effect that have been found includes, a decrease in heart rate, blood glucose and lactate concentrations (38).

Vitamin B2 (riboflavin)

Riboflavin is a nutrient that has been found to help in fat metabolism via the electron-transport chain (39) and an antioxidant (40). It is also one of many nutrients that helps in the production of red blood cells. Levels of riboflavin has been found to diminish during exhaustive exercise (41).

Vitamin B3 (niacin)

Niacin is otherwise known as vitamin B3 and in an antioxidant. Research studies have shown that niacin supplementation increases growth hormones in response to anaerobic exercise (42) as well as a reduction in fasting triglycerides (43). An increase in fasting insulin has been found due to a decrease in insulin sensitivity (44). Further research is needed for this supplement in order to understand the mechanisms.

Vitamin B6 (pyriodoxine)

The active form of vitamin B6 is known as P-L-P (45), which is stimulated by exercise (46). During exercise the body relies on the liver to produce glucose via glycogenolysis, for which vitamin b6 is essential for, and is an integral part of the glycogen phosphorylase enzyme and thus will provide energy to the bodies’ muscles (47).

Vitamin B9 (folic acid)

Folic acid is also known as folate is a water soluble mineral that, along with other nutrients is necessary for red blood cell production (48). It can also help regulate nitric oxide levels in the blood (49).

Vitamin B12 (cyanocobalamin)

Research studies on vitamin B12 have found that it is required for red blood cell production (50), Protein synthesis and the repair and maintenance of tissue cells. (51).

Calcium

Calcium is a vital part of dietary consumption in order to aid growth and maintenance of bones (52). Other important benefits of calcium include helping blood clotting (532), heart contractions (54), lungs (55) and muscles to function properly (56), this is due to calcium binding with phosphate to create calcium phosphate (57).

Magnesium (magnesium oxide)

Magnesium has been found to be used for 300 biochemical reactions in the body (58). It has been found to maintain muscle function (59), supports a healthy immune system (60), keeps the heart beat steady (61), and helps strengthen bones (62). It has also been found to maintain blood glucose levels (63) and aid in the production of energy and protein.

Iron (ferrous fumarate)

Ferrous fumarate is also known as iron sulphate, common uses for this ingredient are for people with iron deficiency. Iron levels have been found to decline due to exercise (64) with findings showing that it can help with fatigue (65).

Zinc (zinc oxide)

Zinc has been identified as a factor for many enzymes responsible for the synthesis, storage and release of insulin (66), with increases in lean body mass while fat mass either remains stable or decreases, depending on the degree of baseline zinc deficiency (67). With this evidence is has been shown that this ingredient is important for the growth and development of body tissues as well as this a variety of biological processes including wound healing and muscle cramps (68) have been found.

Iodine

Iodine is an essential element as the body cannot produce it. It has been found that iodine can aid in weight loss as it is needed by the thyroid gland to produce hormones (69).

Sucralose 

Sucralose is a sweetener that is calorie free. This ingredient is used in many products and is used to make the product taste sweeter and does not have any nutritional benefit. 

Protein World Slender Blend has a wide range of ingredients that can help aid weight loss and toning, which supports the claims that are made. In addition, this product can help to provide energy which can prove useful when needing to prolong exercise sessions. This product can be consumed either pre-or-post-exercise. This product has no banned substances when referring to the WADA prohibited list when observing the label / ingredients posted on the website.

*NOTE – This product has not been tested in a laboratory and may contain other substances that may not appear on the label

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