According to the World Health Organisation (WHO) Global Health Observatory data, at least 2.8 million people die each year from problems associated with overweight and obesity. These conditions have a variety of negative effects on the metabolic system, impacting blood pressure, cholesterol, triglycerides and insulin resistance.
A correlation has been demonstrated between elevated body mass index and the development of a number of cancers such as breast, colon, prostate, kidney and gall bladder. While this problem has traditionally been associated with western countries, emerging data is showing growing trends toward overweight and obesity in Southeast Asia. These upward trends are being reflected more prevalently among women, who are showing roughly double the frequency in obesity.
It is important to note that the process of weight loss is extremely complex and unique to every individual. Efforts have always been made to devise guidelines that will suit the masses; however, as with all areas of biology, such generalised population-based advice can never be sufficient for each person. It is important to address all aspects of diet, lifestyle, health status and genetics.
Observational studies have detected that, for many, the inclusion of low-fat dairy products in a balanced diet, can contribute to healthy weight management. Epidemiological studies have shown that people who regularly consume moderate quantities of dairy products tend to have a lower body mass index (BMI).
This may be influenced by other factors such as a tendency toward other healthful life choices associated with those who choose to eat dairy. However, such findings indicate the potential for dairy ingredients and body weight management. This article looks at the data available supporting the mechanism of action for dairy ingredients in this respect.
From a biochemical perspective, weight loss should be achieved by enforcing a calorie deficit, meaning that by decreasing calorie intake and increasing output, weight loss will occur. This may work for most but is too simplistic and the body is complex.
Long-term solutions for healthy weight management require a more comprehensive approach. It is now wellunderstood that muscle maintenance is key for healthy weight management. The simple idea of energy deficit for weight loss, or energy balance for weight maintenance, fails to address many important elements: type of weight loss, diet composition and exercise.
Type of Weight Loss:Weight loss can occur through loss of fat, water or, undesirably, muscle. Weight loss through loss of muscle has a direct impact on metabolic or other health aspects. Greater muscle mass keeps the body’s basal metabolic rate (the number of calories needed at rest) elevated: more muscle requires more calories. Therefore if significant muscle loss is allowed to occur, fewer calories will be required keep the body running on a day to day basis and it becomes more difficult to achieve that energy deficit.
Diet Composition:A high sugar diet can be very low calorie, however over consumption of glucose has many negative effects on the health. Furthermore, muscles require more than glucose to trigger the pathways that tell its fibres to grow and repair, therefore such a diet will not promote growth or repair of muscle, meaning that muscle loss can occur during the weight-loss period.
Exercise:The type of activity used to achieve increased caloric output is highly relevant. Not all exercise is equal. Catabolic (promotes growth) movement is required for muscle gains. Take for example a thirty minute walk, this will utilise energy so calories will be burned but it will not contribute to the building of muscle, whereas a thirty minute cycle on hilly terrain will engage far more muscle fibre contraction and will therefore result in muscle growth.
Maintaining Muscles Through Protein Intake
So it is clear that muscle matters. However, by a cruel stroke of nature, as we get older it becomes more difficult to hold onto that muscle. Sarcopenia (muscle loss or wasting associated with aging or prolonged periods of inactivity such as throughout recovery from an immobilising injury) comes into play.
This means that for both thin and large individuals, there needs to be an emphasis on maintaining muscle mass through diet and strength-focused exercise. All-in-all, you want to lose fat and retain muscle, so when discussing ‘weight loss’, it is really ‘fat loss’ that is the real goal for achieving optimised metabolic function and overall health.
In order to manipulate weight loss to promote muscle maintenance and encourage fat loss, protein intake must be adequate: moreover the right kind of high biological value or ‘complete’ proteins must be present.
Milk is a naturally abundant source of protein. It is composed of two main types: insoluble casein and soluble whey. Currently there is considerable use of dairy proteins in the sports supplement and clinical nutrition industries. This is due to the high quality nature of milk the proteins. They are considered ‘complete’ because they have the full spectrum of amino acids required by the body.
In terms of promoting catabolism, the branched chain amino acids (BCAAs) leucine, valine and isoleucine, as well as glutamine, all play a role in stimulating mechanisms that tell the muscle tissue to grow. Many studies have indicated the ability of diets with high ratio of protein to carbohydrate to positively influence fat loss and maintenance of fat-free mass. In addition to stimulating muscle growth, the higher satiety value of protein over carbohydrate will also be at play in helping increase calorie deficit.
Beyond the muscle management aspect, milk has other properties that have been noted for their benefits in weight management. Calcium, commonly associated with milk because of its bone-building properties, is also recognised as a useful ingredient in a fat-loss diet.
Multiple studies demonstrate the role of calcium in achieving weight loss and improved body composition (less fat and more muscle). Two of the potential mechanisms at play here include, firstly, the soap-forming ability of mineral salts, such as calcium, with fat globules in the digestive tract, preventing some degree of absorption and thereby lowering calorie intake. Secondly, there are some potential hormonal interactions triggered by calcium that indirectly increase fat breakdown (lipolysis) in the body’s fat stores.
These beneficial qualities from key milk fractions can exist simultaneously in a blend, consisting leucine, bioactive peptides and calcium, such as in Prolibra. This combination has been shown in a randomised, double blind, human clinical study to increase fat loss while sparing the loss of lean muscle in obese subjects undergoing weight loss regimes.
During a 12 week study, subjects were restricted to a daily intake of 500 calories. They were instructed to consume the aforementioned blend which includes 10 g total protein or control (calorie-matched maltodextrin) 20 minutes before breakfast and 20 minutes before dinner.
As expected, both groups lost significant weight, however only the experiment group lost significantly more body fat and retained significantly more muscle than the control group. Achieving weight loss without significant muscle loss is an ideal way to help avoid rebound weight gain because the basal metabolic rate is not being hindered.
Dairy And Metabolism
In overweight and obesity, the metabolism suffers in that a number of mechanisms function poorly, below par or, in extreme cases, completely fail causing a disease state. Type II Diabetes occurs when insulin production is reduced or when receptors in the tissues no longer respond to insulin. Both of these scenarios lead to blood sugar spikes (hyperglycaemia) and falls (hypoglycaemia). This aberrant glucose pattern is damaging to the tissue and organs over time.
Many studies have shown the ability of milk proteins, especially hydrolysed peptides, to improve glucose metabolism by inducing short-lived increases in insulin production that can help clear blood sugar levels and thereby deal with hyperglycaemic episodes. A study in 2009 also showed how adding a glycaemic index-lowering peptide (GILP) fraction derived from milk to a glucose drink successfully lowered the glucose area under the curve, a standard measurement for monitoring healthy glycaemic function.
Of course, dairy ingredients in the diet will only be beneficial in those who can tolerate their digestion. People with lactose intolerance and other dairy-averse conditions, will not benefit from including such products. However, such individuals can still benefit form including high biological value proteins in their diet, as these do not have to be animal-sourced. Combinations of many plant-based proteins such as pea, flax, chia, soy and algal proteins can be used to deliver the full quota of amino acids to enable muscle maintenance.