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Article:
Is the new 'High-Protein Low-Saturated Fat' Diet The Answer To Weight Loss? by: John Tiniakos The heated debate, within diet circles, that began a few years ago and continues today is over the effectiveness of the high-protein, low-carbohydrate, type diet versus its counterpart, the high-carbohydrate, low-fat diet. To the delight of the Atkins diet enthusiasts, recent studies have suggested that a diet high in protein and low in fat has a greater effect on diet induced thermogenesis than a high carbohydrate low fat diet. Before we go further we need to familiarize you with a few terms we will be discussing in this article. Your total daily energy expenditure (TDEE) is the total energy your body burns in a day. TDEE consists of 3 components: diet induced thermogenesis (DIT), basal metabolism, and physical activity. DIT is the increase in the body's temperature that is caused by the digestion and absorption of a meal. This rise in temperature results in calorie burning. Yes, we actually burn calories simply by eating and scientists have long believed that DIT may be a factor, in reducing obesity; and that obese people may have defective DITs - although this hasn't been proven yet. Once scientists identify the link between DIT and obesity on a molecular level, it could essentially pave the way for the development of drugs in the treatment of obesity. That's still however, in the future. In a recent study at the University of Arizona, published by the American College of Nutrition, a group of young healthy women were given 2 sets of diets. (1) One diet was high in protein and low in fat and the other was high in carbohydrate and low in fat. Scientists were trying to compare the thermic effect (DIT) of protein versus carbohydrate during the digestion and absorption of meals. Keep in mind, as the body's temperature increases (by DIT), so does the number of burned calories. Evidence from this study showed that postprandial (following a meal) thermogenesis increased 100% more with the high-protein low-fat diet versus the high-carb low-fat diet. Although protein had a greater effect on DIT, the study did not evaluate weight loss or the long term effects of this type of diet. The results did suggest that this type of diet may have a positive effect on weight loss. Scientists concluded that a diet high in protein, moderate in carbohydrate and low in fat contents may promote a higher rate of weight loss compared to the high carbohydrate, low fat diet. On the other hand, they also warn that high protein diets may affect kidney function in those that have kidney conditions, but not in healthy individuals. Furthermore, they recommend daily protein intake should not exceed 2 grams per 1 kilogram of body weight. The American daily average is 1 gram per 1 kilogram. Further studies are required to assess the long term effects of high protein, low fat dieting. It is important to keep in mind, however, that DIT or the thermic effect of a meal only represents 3-10% of total daily energy expenditure (TDEE). So we must keep things in perspective. Basal or resting metabolism accounts for up to 70% of TDEE and energy expenditure from exercise is responsible for the rest. Logic dictates, therefore that these two take precedence over DIT. The other big influencing factor in weight loss is the reduction of daily food intake. Let's look at the input/output equation: x (Input) '“ y (Output) = z. Daily output and total daily energy expenditure (TDEE) are the same thing. If you ate fewer calories (x) than your body burned (y), z would have a negative value. If you consumed more calories than your body expended, z would be positive. A negative balance in the equation results in weight loss, a positive value causes weight gain. It's that simple. In the above study, the high protein low fat type diet involves 2 factors of Input: Food composition and food quantity. In this diet, food composition (food selection) consists of a certain combination of macronutrients (high protein, low fat). Food intake (Input) affects the DIT which causes a certain increase (energy expenditure) on the Output part of the equation. And, as food composition varies so does the DIT. Food composition, though, can only have a limited effect on DIT. Remember DIT only represents 3-10% of the TDEE (Output). And food composition (high-protein, low-fat), accounts for a percentage of DIT, which represents even a smaller value. Food quantity, on the other hand, can have a tremendous effect on the equation '“ as it increases, the balance becomes more positive. If it surpasses TDEE then you gain weight - quite independently of DIT. As a result, there can be a downside with respect to DIT involving the high-protein low-fat diet or any diet for that matter. With this diet, as protein intake increases so does the DIT. The problem is, however, that the food quantity (Input) also increases. The point here is that there is a limit to the amount of protein you can ingest before your body starts storing it as fat. Because DIT doesn't account for expending a lot of calories (3-10% of TDEE), and food composition (high-protein, low-fat) accounts for a percentage of DIT, there's only so much protein you can ingest before you start getting a surplus of calories. And excess dietary protein just as excess carbohydrate or fat is stored as fat in the body's adipose tissue. The only other factor that can compensate for the excess of protein intake is an increase in exercise participation. Although, that would defeat the purpose for obvious reasons. Physical activity, however, can have a large effect on the Output part on TDEE (Output). Not only does it account for a much larger energy expenditure than DIT, countless of studies have shown that regular physical activity actually increases basal metabolism, which accounts for up to 70% of TDEE. As a result, regular exercise participation essentially has a compounding effect on the calorie burning process. As we can see then, the bulk of weight loss and weight gain comes down to the quantity of calories ingested (Input) and calories burned (output). Furthermore, exercise and metabolism are responsible for approximately 90%-97% of TDEE. Energy expenditure from DIT is almost insignificant in comparison. DIT is just not effective enough to produce a negative caloric balance independently of total caloric intake, energy expenditure from exercise and basal metabolism - especially for most overweight individuals. And it would be unrealistic for overweight or obese people to rely exclusively on DIT to lose weight. These people are either overeating, aren't active enough or have low basal metabolic rates - or a combination of all three factors. So, it still looks like there's no easy way out '“ you actually have to work, if you you're going to lose weight. The easiest way to achieve that is with the efficient use of all Input and Output components. That also means you must know your priorities. Most of your efforts should be spent in finding an adequate balance between a reduction of total daily caloric intake and a sufficient level of physical activity. And emphasis on DIT should take on a secondary role. But wait, before you put on your running shoes and begin another diet plan, you might want to hear some very interesting news. There are certain cultures around the world whose diets contain just as much fat and carbohydrate (if not more) as in the American diet. Yet they are slimmer, and have much fewer occurrences of heart disease and cancer than their American counterparts. Recent studies have shown that people in certain Mediterranean regions and in France manage to stay healthier and are less obese than those in other western countries. Let's look at the French first. In a study by Adam Drewnowski of the University of Michigan, scientists examined the eating habits of '1
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