If you gathered from my last post that all carbs are the nemesis of successful weight-loss programs then I am sorry to give you that impression. Actually carbs are a very important component of our diet and half our calorie intake must come from carbs. Fruits, we all know, are very healthy and packed with essential vitamins and minerals, not to mention anti-aging antioxidants, have plenty of carbs in them and everyone should have at least 2-4 servings per day. Even the RDA food pyramid suggests 8-12 servings of carbs per day.
So obviously all carbs aren’t created equal! This is where Glycemic Index (GI) of a carb comes into play. In simple terms GI of a carb is its ability to affect the blood’s glucose level relative to glucose. The GI value of glucose (or dextrose) is assigned 100. Another concept is the Glycemic Response (GR) which is a measure of how fast blood glucose levels rise with the consumption of a certain type of carb. So as you may have already guessed the higher the GI value of a carb the faster the GR in the body and the faster the insulin response of the pancreas. For example a boiled potato (GI 85) spikes our blood glucose level in milliseconds while garbanzo beans (GI 28) takes about an hour to gradually raise the blood glucose levels. This would mean that eating a boiled potato would spike your insulin level in a matter of few minutes and as soon as the insulin levels rise it would start converting and stacking away the excess blood glucose into your fat cells, provided no physical activity (or the need for the excess glucose) was being performed to utilize the glucose . Once all the blood glucose from the potato was stacked away into your fat cells the residual insulin would still keep acting on your glucose levels further reducing its supply and making you hungry in the process. And once you repeat the carb eating process the same insulin cycle continues over and over again. Over a period of time this causes a sort of insulin resistance in your body where more and more insulin needs to be released to counteract the same glucose levels. In extreme cases the pancreas just give up and stop the insulin release that leads to other complications of elevated glucose levels, as in people with diabetes. On the other hand something like garbanzo beans would slowly raise the blood glucose level and chances are the body would be using up the small amounts of glucose that is produced for its normal day-to-day activity without ever converting to fat.
In order to start burning the stored fat, calories burned in the body should exceed the calorie intake. A sensible exercise program coupled with a caloric restrictive diet can accomplish that. Secondly and more importantly in order to stop accumulating any new fat, the calories should come from sources that don’t cause sudden insulin spikes, i.e., from low GI sources taken in small quantities over several small meals. This way insulin levels are stabilized to a steady level through out the day and there is no additional fat accumulation. That is easier said than done especially for someone like me that spent a good part of life believing in the high-carb-low-fat dogma for fat loss. I never paid attention to the carbs I ate as long as they were low in fat. I cut down on fat drastically while consuming big portions of white bread, rice, potatoes and even soft drinks (since they were ‘zero fat’) and you don’t want to know the results of this ‘sensible diet’.
The concept of South-beach is to get ones body off the insulin dependence in the initial 2 week phase. This increases ones metabolism since the body has to now work harder in order to convert calories from low GI sources and proteins. During this phase all the calories come from very low GI foods such as Garbanzo beans, lentils, lean meats, fish, nuts etc, spread out over several small meals throughout the day. During the first 2-3 days the body is craving the high insulin levels and it might seem like one is perpetually hungry and ‘weak’ but once the body gets past this threshold it becomes easier and the body doesn’t crave the insulin levels. After about a week on this diet one would no longer crave the usual comfort carbs (rice, potatoes, and bread) and it would seem like you are never hungry enough to indulge in binge eating. Life is easier after that. People, depending on how over-weight they were to begin with, lose an average of 10-20 lbs in the first two weeks. After the initial 2 week phase one goes on a phase 2 where some of the carbs that were forbidden in phase 1 are re-introduced in the diet, like whole wheat bread, whole wheat pasta, fruits etc. Phase 2 can be continued for as long as one desires and there is typically continued weight loss of about 1 lb/week until weight loss stabilizes. At that point some go on a phase 3 where some more of the carbs are introduced and typically you are allowed ice cream and some other desserts. Phase 3 is very easy and can be practiced for life and as long as you have a balanced meal of low to moderate GI carbs, healthy fats and protein.
If phase 1 sounds too difficult (and believe me it is) then one can simply begin with phase 2 coupled with an exercise regimen that will help boost metabolism and keep insulin levels low (remember exercise lowers insulin by consuming excess blood glucose). With this approach the same goal is achieved as phase 1 where the metabolism is boosted and the body gets off insulin dependence. The best of course would be to go into phase 1 coupled with an exercise regimen, but that is even more difficult especially in the first week of adaptation phase where perceived energy levels are low and exercising might be next to impossible.
Here is a pretty comprehensive listing of the GI values of the most common foods.
http://www.gilisting.com/glycemic-index/2007/01/gi-index-table.html
Use this list to pick your favorite food and stick to the low to moderate GI foods. Occasional indulgence in high GI comfort foods is allowed after physical exercise as at that point the insulin levels are low. Better even combine those high GI foods with healthy fats and proteins so that the overall effect of high GI is blunted as proteins and fats hinder the quick absorption of high GI foods and keep you fuller longer. Happy eating and exercising and fat loss….Until next time.
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Skinny Without Willpower
Wednesday, April 1, 2009
Sunday, March 15, 2009
THE TRUTH ABOUT FAT, CARBS AND WEIGHT GAIN
How many times have you heard “The fat in pizza will make you fat” or “the fat from deep fried foods will make you fat”? Countless, right? But truth couldn’t be farther than this. I myself believed, for the longest time, that a high-carb low fat diet is the holy grail of weight loss. But little did I know...
The recent interest in Atkins and South Beach diet and all the related success stories have compelled researchers to re-think the “fat will make you fat” mentality. To understand this, one has to understand the mechanism by which fat is stored in the body and the role of Insulin in weight gain. Fat in the diet converts to fatty acids and carbs in the diet convert to glucose in the blood stream. The role of pancreas in the body is to regulate blood glucose levels and when ever the glucose level in the blood rises, the pancreas produce insulin to counteract it. The insulin then takes away the blood glucose and converts it into glycogen that is stored in the liver and the muscle cells. Once the muscle cells and liver reach their full glycogen storage capacity any excess glycogen converts to fat. This is where added muscle mass from weight training comes in handy for storing the glycogen and prevent fat conversion. Fat doesn’t get stored as fat until it is acted upon by insulin and figure 1 shows how the blood glucose level rises with time after ingesting a carb or fat meal. It’s clear that fat doesn’t cause a rise in blood glucose level and neither does it elicit an insulin response from the pancreas as illustrated in figure 2.
The recent interest in Atkins and South Beach diet and all the related success stories have compelled researchers to re-think the “fat will make you fat” mentality. To understand this, one has to understand the mechanism by which fat is stored in the body and the role of Insulin in weight gain. Fat in the diet converts to fatty acids and carbs in the diet convert to glucose in the blood stream. The role of pancreas in the body is to regulate blood glucose levels and when ever the glucose level in the blood rises, the pancreas produce insulin to counteract it. The insulin then takes away the blood glucose and converts it into glycogen that is stored in the liver and the muscle cells. Once the muscle cells and liver reach their full glycogen storage capacity any excess glycogen converts to fat. This is where added muscle mass from weight training comes in handy for storing the glycogen and prevent fat conversion. Fat doesn’t get stored as fat until it is acted upon by insulin and figure 1 shows how the blood glucose level rises with time after ingesting a carb or fat meal. It’s clear that fat doesn’t cause a rise in blood glucose level and neither does it elicit an insulin response from the pancreas as illustrated in figure 2.
Figure 1. Blood glucose levels after 100g of carbs or 40g of fat. [Ref 1]
Figure 2. Blood insulin levels after ingesting 100g of carbs or 40g of fat. [Ref 1]
The other aspect of this scenario is the delayed response of the glucose/insulin system. From figure 1 you can see that the blood glucose levels come back to normal levels within about 90 or so minutes while the insulin levels remain high, this causes your blood glucose to fall below normal levels, making you hungry again. As a result you consume more carbs. This sets off a vicious cycle, which if continued for long periods of time, makes the body insulin resistant and the more you eat the more insulin gets triggered causing more weight gain and more hunger pangs, making obesity inevitable. [Ref 2, 3]. The other affect of insulin is to suppress the production of Lipase, a hormone responsible for metabolizing fat in the cells into fatty acids.
The only way fat from diet gets stored as fat in the body is when insulin acts upon fatty acids and drives it into cells as stored fat. And from figure 1 and 2 its easy to see why fat by itself cannot contribute to weight gain. But if fat is consumed with carbs then it would contribute to fat gain. No wonder pizza, donuts and cheeseburgers are some of the most notorious weight gain foods because they combine fat with carbs.
So now that you have gained weight the next question is how to lose it? Well, the only way to lose fat is to metabolize it into fatty acids and use up as energy. This will happen in one and only one condition, that is, when you deprive the body of its present source of energy, glycogen. This can only happen by:
1) Starving.
2) Limiting the consumption of carbs and relying on fat and protein as the primary source of energy.
Obviously the first approach doesn’t work as it slows the metabolism and forces the body to go into starvation mode, thus making further fat loss impossible. The second approach is the gist of all the modern weight loss diets. The Atkins relies on protein and fat as the primary source of energy with very little carb. The South-Beach relies on high protein, ‘healthy’ fats and limited quantities of ‘healthy’ carbs for fuel. But what is a ‘healthy’ carb? This begs the question: are all carbs created equal? This is a topic for my next post…
References:
1. Robertson MD, Henderson RA, Vist GE, Rumsey RDE. Extended effects of evening meal carbohydrate-to-fat ratio on fasting and postprandial substrate metabolism. Am J Clin Nutr 2002; 75: 505-510.
2. Bruning JC, Gautam D, Burks DJ, et al. Role of brain insulin receptor in control of body weight and reproduction. Science 2000; 289: 2122-5.
3. Odeleye OE, de Courten M, Pettitt DJ, Ravussin E. Fasting hyperinsulinemia is a predictor of increased body weight gain and obesity in Pima Indian children. Diabetes 1997; 46: 1341-5.
Tuesday, March 10, 2009
AEROBICS OR WEIGHT TRAINING
What’s better for fat loss: Aerobics or Weight Training?
Energy expenditure in the body from any activity follows one of three pathways:
1) Aerobic: Any activity that is performed at a low to moderate intensity for more than 90 seconds, allowing oxygen to release energy through metabolism, is usually called an aerobic activity or more commonly referred to as cardio.
2) Anaerobic (ATP-CP): Any activity that utilizes Adenosine Tri-Phosphate (ATP) stored in the muscle cells. ATP is the immediate source of energy and is exhausted in about 3-5 seconds during a muscle contraction.
3) Anaerobic (Lactate/post ATP): As soon as the ATP in the cells is exhausted the body resorts to the breakdown of glucose for energy. This results in the production of lactate and hydrogen ions, ultimately leading to fatigue.
Cardio or aerobic exercise uses the Aerobic energy pathway while resistance or weight training uses the two anaerobic energy pathways. During exercise cardio burns about 20% more fat compared to weight training. But the flip side to this is that weight training results in increase of muscle mass that continues to burn calories in the rest state, thereby increasing your basal metabolic rate (BMR). Muscle cells are active tissues that require the conversion of blood glucose (from food) to glycogen thereby restricting the conversion of food calories to fat. So considering the long term fat burning capabilities of weight training vs. cardio, the former is the clear winner.
Both types of exercises have some pros and cons. The pros in favor of cardio are:
1) Increased cardiovascular function: the increase in the oxygen requirements when doing cardio increases your heart-rate since there is a higher need for oxygen carrying blood supply to the working muscle tissue.
2) Decrease in body fat: cardio exercises increase the capacity of working cells to absorb oxygen and glucose that are necessary for energy expenditure. This lowers blood glucose thereby reducing the calorie to fat conversion during the activity.
3) Cardio is fun and safe: Swimming, bicycling, jogging, brisk walking can all be fun.
The cons against cardio are:
1) Decreased muscle mass: The human body is an intelligent system and any endurance based exercise will, in order to maximize the efficiency, shed any unnecessary weight be it fat or muscle. So in effect cardio doesn’t discriminate between fat loss and muscle loss and only the muscles involved in the endurance exercise will be partially spared while the other muscles will atrophy. That’s why marathon runners have puny little chests and toothpick arms and not very big legs either.
2) Decreased strength/power/speed: again related to atrophy of all unrelated muscles.
3) Duration of activity: Aerobics has to be of a certain duration to be effective for fat loss. The energy for the first 20 or so minutes comes from either blood glucose (from food) or from muscle glycogen. Body fat is only used up after muscle glycogen stores are depleted. So in order to burn any fat the aerobics activity has to be done longer than 20-30minutes.
Likewise the pros in favor of weight training are:
1) Increased cardiovascular function: Even though anaerobic exercises don’t require the added oxygen to burn calories but nevertheless require the transport of nutrients like protein, amino acids and blood glucose to the working cells, thereby increasing the circulation and heart rate, although not as much as in a cardio workout.
2) Decrease in body fat: weight training increases muscle mass. The muscle cells constantly convert blood glucose to glycogen thereby reducing the calorie to fat conversion. This effect happens long after the activity has ceased. As a reference about 3lbs of muscle burns 120 calories/day even when it’s inactive. So if you gained 10lbs of muscle (which could perhaps take over a year of intense weight training) you would be burning the same amount of calories per day that a 140lb person would do in a jogging session at 5 mph for 45 minutes every day. Considering that you could be sleeping and still burn as many calories as the jogger, I think it’s a bargain worth shooting for.
3) Increased muscle mass: Isn’t that obvious.
4) Increased strength/power/speed: this one is also obvious. Consider the leg muscle, who do you think is stronger and more powerful and moves faster, a sprinter or a marathon runner? The sprinter of course!
5) Body Sculpting: With weight training you have the flexibility to sculpt your body to desired shape. If you want big arms there are exercises for just that. If you want big chest or shoulders, there are exercises for that. If you want a “V” taper to you upper body, there are back exercises for that. And if you want wash-board six-packs there are exercises for that.
6) Age-reversal effect of Weight Traning: Many researchers have shown that moderate amounts of weight training releases human growth hormone and testosterone, the two hormones that have shown age-reversal effect in humans. In several cases people that performed weight training demonstrated muscle mass, cardiovascular fitness, coordination and bone density comparable to those who were 20 years younger than them.
And the cons against weight training are:
1) Weight training can be dangerous: Its best to have a certified trainer teach the basic moves of weight training for safety reasons especially in compound body exercises like the squat, bench press and the dead lift. Don’t do it based on some videos you have watched on youtube.
2) Weight training is not as much fun as cardio: What is fun about repeatedly moving a certain weight from point A to point B set after set?
Physical fitness is a compromise of cardio-respiratory endurance, strength, flexibility, power, speed, coordination, agility, balance, accuracy and toughness. To pursue fitness excellence you must physically train to “optimize” your performance in all of the physical abilities and not “maximize” your performance in any one ability at the expense of all others.
I believe to get the best results one has to use a combination of both types of training methods. I have found that its best to do cardio and weight training on separate days or at least keep the workouts separate, for example do aerobics in the morning and weight training in the evening or vice versa. No matter which method you choose, remember that the best results come from perseverance and don’t happen overnight so stick to it and the results will follow.
Here is some additional reading on this subject:
http://www.womenshealthmag.com/fitness/cardio-vs-strength-training-workouts?page=1
Energy expenditure in the body from any activity follows one of three pathways:
1) Aerobic: Any activity that is performed at a low to moderate intensity for more than 90 seconds, allowing oxygen to release energy through metabolism, is usually called an aerobic activity or more commonly referred to as cardio.
2) Anaerobic (ATP-CP): Any activity that utilizes Adenosine Tri-Phosphate (ATP) stored in the muscle cells. ATP is the immediate source of energy and is exhausted in about 3-5 seconds during a muscle contraction.
3) Anaerobic (Lactate/post ATP): As soon as the ATP in the cells is exhausted the body resorts to the breakdown of glucose for energy. This results in the production of lactate and hydrogen ions, ultimately leading to fatigue.
Cardio or aerobic exercise uses the Aerobic energy pathway while resistance or weight training uses the two anaerobic energy pathways. During exercise cardio burns about 20% more fat compared to weight training. But the flip side to this is that weight training results in increase of muscle mass that continues to burn calories in the rest state, thereby increasing your basal metabolic rate (BMR). Muscle cells are active tissues that require the conversion of blood glucose (from food) to glycogen thereby restricting the conversion of food calories to fat. So considering the long term fat burning capabilities of weight training vs. cardio, the former is the clear winner.
Both types of exercises have some pros and cons. The pros in favor of cardio are:
1) Increased cardiovascular function: the increase in the oxygen requirements when doing cardio increases your heart-rate since there is a higher need for oxygen carrying blood supply to the working muscle tissue.
2) Decrease in body fat: cardio exercises increase the capacity of working cells to absorb oxygen and glucose that are necessary for energy expenditure. This lowers blood glucose thereby reducing the calorie to fat conversion during the activity.
3) Cardio is fun and safe: Swimming, bicycling, jogging, brisk walking can all be fun.
The cons against cardio are:
1) Decreased muscle mass: The human body is an intelligent system and any endurance based exercise will, in order to maximize the efficiency, shed any unnecessary weight be it fat or muscle. So in effect cardio doesn’t discriminate between fat loss and muscle loss and only the muscles involved in the endurance exercise will be partially spared while the other muscles will atrophy. That’s why marathon runners have puny little chests and toothpick arms and not very big legs either.
2) Decreased strength/power/speed: again related to atrophy of all unrelated muscles.
3) Duration of activity: Aerobics has to be of a certain duration to be effective for fat loss. The energy for the first 20 or so minutes comes from either blood glucose (from food) or from muscle glycogen. Body fat is only used up after muscle glycogen stores are depleted. So in order to burn any fat the aerobics activity has to be done longer than 20-30minutes.
Likewise the pros in favor of weight training are:
1) Increased cardiovascular function: Even though anaerobic exercises don’t require the added oxygen to burn calories but nevertheless require the transport of nutrients like protein, amino acids and blood glucose to the working cells, thereby increasing the circulation and heart rate, although not as much as in a cardio workout.
2) Decrease in body fat: weight training increases muscle mass. The muscle cells constantly convert blood glucose to glycogen thereby reducing the calorie to fat conversion. This effect happens long after the activity has ceased. As a reference about 3lbs of muscle burns 120 calories/day even when it’s inactive. So if you gained 10lbs of muscle (which could perhaps take over a year of intense weight training) you would be burning the same amount of calories per day that a 140lb person would do in a jogging session at 5 mph for 45 minutes every day. Considering that you could be sleeping and still burn as many calories as the jogger, I think it’s a bargain worth shooting for.
3) Increased muscle mass: Isn’t that obvious.
4) Increased strength/power/speed: this one is also obvious. Consider the leg muscle, who do you think is stronger and more powerful and moves faster, a sprinter or a marathon runner? The sprinter of course!
5) Body Sculpting: With weight training you have the flexibility to sculpt your body to desired shape. If you want big arms there are exercises for just that. If you want big chest or shoulders, there are exercises for that. If you want a “V” taper to you upper body, there are back exercises for that. And if you want wash-board six-packs there are exercises for that.
6) Age-reversal effect of Weight Traning: Many researchers have shown that moderate amounts of weight training releases human growth hormone and testosterone, the two hormones that have shown age-reversal effect in humans. In several cases people that performed weight training demonstrated muscle mass, cardiovascular fitness, coordination and bone density comparable to those who were 20 years younger than them.
And the cons against weight training are:
1) Weight training can be dangerous: Its best to have a certified trainer teach the basic moves of weight training for safety reasons especially in compound body exercises like the squat, bench press and the dead lift. Don’t do it based on some videos you have watched on youtube.
2) Weight training is not as much fun as cardio: What is fun about repeatedly moving a certain weight from point A to point B set after set?
Physical fitness is a compromise of cardio-respiratory endurance, strength, flexibility, power, speed, coordination, agility, balance, accuracy and toughness. To pursue fitness excellence you must physically train to “optimize” your performance in all of the physical abilities and not “maximize” your performance in any one ability at the expense of all others.
I believe to get the best results one has to use a combination of both types of training methods. I have found that its best to do cardio and weight training on separate days or at least keep the workouts separate, for example do aerobics in the morning and weight training in the evening or vice versa. No matter which method you choose, remember that the best results come from perseverance and don’t happen overnight so stick to it and the results will follow.
Here is some additional reading on this subject:
http://www.womenshealthmag.com/fitness/cardio-vs-strength-training-workouts?page=1
Wednesday, January 28, 2009
Fat loss and fat intake
Question:
What is worse for fat gain; 1 can of soda with 120cals and zero fat or one 2 slices of cheese with about 120cals and 8 grams of fat?
Answer:
One can of soda!
To understand this we have to understand the effect of insulin in the body. The role of insulin in the body is to regulate the blood sugar levels and to keep it within a fixed range. When the blood sugar rises in response to simple sugars the pancreas produce insulin to take out the sugar from the bloodstream and store it as fat. The sugar in the soda gives the blood a quick insulin spike which if not metabolized converts to fat quite easily, while the fat and protien in cheese dont spike the insulin and dont easily convert to fat.
So in order to lose weight one has to make sure that the blood insulin levels dont rise abruptly. Its better to keep steady insulin levels through out the day. Thats the reason 5-6 small frequent meals are better for weight loss than one or two big meals a day.
More later......
What is worse for fat gain; 1 can of soda with 120cals and zero fat or one 2 slices of cheese with about 120cals and 8 grams of fat?
Answer:
One can of soda!
To understand this we have to understand the effect of insulin in the body. The role of insulin in the body is to regulate the blood sugar levels and to keep it within a fixed range. When the blood sugar rises in response to simple sugars the pancreas produce insulin to take out the sugar from the bloodstream and store it as fat. The sugar in the soda gives the blood a quick insulin spike which if not metabolized converts to fat quite easily, while the fat and protien in cheese dont spike the insulin and dont easily convert to fat.
So in order to lose weight one has to make sure that the blood insulin levels dont rise abruptly. Its better to keep steady insulin levels through out the day. Thats the reason 5-6 small frequent meals are better for weight loss than one or two big meals a day.
More later......
Tuesday, January 27, 2009
Fitness Lifestyle
I have been a fitness enthusiast for 15+ years but as I grow old I realize that fitness is not a part time endeavor that one persues to get from shape 'A' to shape 'B'. Fitness is rather a way of life or a lifestyle that has to be incorporated as a part of one's daily routine. Fitness doesn't only mean a fit body but also a fit mind. In this blog I wish to share my views and opinions about ones overall fitness and how one can have a balanced approach to fitness. The purpose is not to make a model out of anyone but rather to enable one to lead a healthier, fuller and satisfactory life. Its the first time I have ever blogged so please bear with me if I say something offending and feel free to comment.
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