There is an old saying that "You are what you eat". This appears to be a self-evident truth. However, our body is more complicated than this. Our body is like a chemical lab that has thousands of reactions going on simultaneously at any given second. It is not surprising that what we eat might turn into something we haven't thought about after some of these reactions.
Our goal is to loss fat. Therefore while there are hundreds of reactions happening in our body, we should only be concerned about nutrients that have the potential to be turned into fat. It turns out that after my intensive research in the field of metabolic biochemistry, in addition to fat, protein and carbohydrate are the two major nutrients that has the potential to become fat.
In this section, I will first tell you how proteins, carbohydrates and fat are turned into fat and then get stored. Then I will devise a diet that while lowering your chance of getting fat accumulated, it won't make you starve and allow you to function at full capacity.
Carbohydrates are broken down into glucose in intestine. Glucose provides immediate energy for our brain and red blood cells. Execessive glucose are transported to liver and converted into glycogen and stored in liver and muscle. On average, each person can store 2,000 calories of glycogen in their body. That is about 500g of carbohydrate.
When we don't have any more capacity to store glycogen, excessive glucose will be turned into fat for storage. During this conversion, 23% of energy stored in glucose is lost. Unfortunately, such conversion is accounts for only 5% of the carb we consume. The rest of the carb is either stored as glycogen or oxidized to spare fat burn.
Proteins were broken down into amino acids (protein is by definition a chain of amino acids) and absorbed in the small intestine. Amino acids are then transported to all over the body to build the proteins to maintain our health.
Excessive amino acids are then transported to the liver. Some amino acids can only be converted to glucose. Some can only be converted to fatty acids. While the others can be converted to either glucose or fatty acid. The glucose generated will be either stored as glycogen or oxidized for energy. Some fatty acid generated will also be oxidized while the remaing ones are stored as fat.
Fat metabolism is relatively simple. If it is not used for biological processes or energy, excess fat will be stored. The storage cost is about 2.5% of the energy stored in dietary fat. When we need to use them, they are broken down into glycerol and fatty acids. Glycerol is transported to liver and converted into glucose. Fatty acids are transferred to cells and burned with oxygen for energy.
Insulin is a hormone that regulates blood sugar level. When we consume carbohydrates that are readily absorbed (e.g. glucose), then our blood sugar level will shoot up. To bring the blood sugar level down to normal, our pancreas secrets insulin which:
You can see that insulin is a bad hormone for fat loss because it inhibits the release of fatty acid from fat tissue. As a result, it forces our body to burn more carb than normal.
Glugacon is a related hormone that does almost the opposite. Glucagon is secreted by our pancreas when our blood sugar level is too low. However, its effect is mostly confined to liver. Glucagon serves the following functions:
To measure the effect of carb-rich food on insulin secretion, scientist defined a new concept called Glycemic Index (GI). It is defined to be the level of blood sugar spike after ingestion of carb-rich food with glucose as the reference food with GI of 100. For more detailed definition, please go here. GI depends only on food type and how it is prepared but it is independent of its weight. In general, if majority of your food is low GI, your body should have less insulin and hence more fat is burn.
However, GI doesn't measure the absolute value of insulin spike. To measure that we need the concept of Glycemic Load (GL). Glycemic Load is defined to be GI × amount of carb (grams) devided by 100. For example, if you eat a 170g banana with GI 51 that has 35g of carb, GL is 51×35/100 = 17.85. It is said that you should try to minimize the GL of each meal such the per meal GL is less than 20. To achieve this while keeping a high level of carb intake, it is better to split your meals to five or more meals per day. By doing this, you can maintain a high fat burn rate through out the day.
For people who enjoy carb-rich food with high GI, there are several ways to reduce GI: 1) mix the carb-rich food with protein/fat-rich food; 2) increase acidity of the carb-rich food. The former explains why eating processed sugar products are bad for fat loss. Since processed sugar products are very sweet, no one will eat it with protein/fat-rich food or add vinegar to it. The latter explains that because sushi rice is made with vinegar, the Japanese don't get fat despite eating a lot of high GI white rice in the form of sushi.
For some people who has the condition of hyperinsulinism (ie secrets too much insulin when blood sugar level spikes), consumption of high GI food can cause low blood sugar level because too much insulin was secreted. As a result, the body secrets Glucagon and triggers a hungry feeling that causes you to eat more than needed. Obviously this is bad for fat loss.
Ingestion of protein causes our body to secret BOTH insulin and glucagon. The net result of this is that we now have more protein synthesis and inhitibits the release of fatty acid from fat tissue. Therefore, protein intake also slows down fat burn. Finally, since insulin and glucagon counteracts with each other, protein intake has very little effect on blood sugar level. [NM03]
What we learned from above is that excessive protein and carbohydrate will inhibit our body's ability to burn fat as fuel. Another fact is that fat does make you fatter because it can't be converted to protein or carb. However, protein can be used for non-energy purposes and some carbohydrates can be stored as glycogen provided that you exercise to use up some of the glycogen stored in muscle. That means we should have a diet that gears toward less calories from fat and also lower total calories per day, ie low fat low calories diet. That should minimize the amount unused carb and protein being turned into fat and also minimize the fat storage.
| Nutrient | Calories /gram | Basic Functions | Effects | ||||||||
| Optimal | Deficiency | Overdose | |||||||||
| Protein | 4 | The nanomachines of our body. Basically life is just nothing but the function of proteins | Sedantary adult 0.8g per kg. Edurance Athletes 1.2-1.4g per kg weight depending on intensity. Body Builders 1.6-1.7g per kg weight [N02]
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|
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| Carbohydrate | 4 |
| adult: 1/3 of Daily Calories Needs if sedantary. Add extra carb needs based on exercises
adult: less than Optimal | Fat | 9 | adult: only need 15kcal from Omega-6 Fatty Acids and 5kcal from Omega-3 Fatty Acids if your fat store is abundant | | ||||
It is well documented in the literature that when you consume significantly less calories than is needed, your body will reduce its basal metabolic rate to slow down energy consumption. Some of this slow down can become long-term. As a result, when people reach their weight goal and then start eating their pre-diet meals, they gain back all the weight and more. This phenomenon is widely known as Yo-yo dieting. [EEP00]
Yo-yo dieting is caused by a long term reduction in basal metabolic rate. There are two possible causes: 1) lack of carb; and 2) lack of both carb and protein.
It is known that a hormone called cortisol will be secreted after feeling stress for five or six consecutive days. In addition to other non-nutritional stress, a long period of insufficient carb intake can causes a stress called hypoglycemia (ie low blood sugar). This stress will then trigger the release of cortisol. Under sufficient protein supply, hypoglycemia will also increase secretion of growth hormone. Cortisol breaks down muscle proteins for amino acids whereas growth hormone synthesize muscle proteins from amino acids. However, low blood sugar level promotes muscle breakdown, so the net effect is gradual muscle breakdown. [TEP04] Since each kg of muscle requires 22kcal/day to maintain [BPAHN00], loss of muscle means a long-term decrease in basal metabolic rate unless you gain back the muscle through weight training. This causes the problem of Yo-yo dieting.
If we are now lacking protein in addition to carb, cortisol will now be unopposed by growth hormone because growth hormone requires protein to make. The muscle loss will be more pronounced and this results in . a more severe form of Yo-yo dieting.
The minimum daily intake for protein recommended by USDA is about 0.8g per each kilogram of body weight for people with sedantary life style. For people who have endurance training regularly, it is 1.2-1.4g per each kg of body weight depending on how intense your training is. For people who are doing weight training, the minimum daily intake goes up to 1.6-1.7g per each kilogram of body weight depending on how intense your workout is. [N02] Note that [DRI05] concludes that normal level of physical activity (e.g. up to 5 hours per week of endurance training or non-competitive body building) doesn't require more than 0.8g/kg/day of protein. I think the added dosage mentioned by [N02] is only for people who are competitive atheletes.
Insufficient protein intake due to dieting can reduces the rate of protein synthesis. One of the use of protein is to make lipoprotein to carry hormones secreted by thyroid gland to their destination. Thyroid hormones are known to be the major player behind the regulation of basal metabolic rate. Failure for the thyroid hormones to reach their destination results in lower basal metabolic rate. But this effect can be reversed once you start consuming protein again. [NM03]
As to carbohydrates, research shows that one third of our energy comes from carb and the remaining from fat during sleep or relaxed states (e.g. watching TV). That means if we have a sedantary life style, we only need one third of our Daily Calories Needs from carb. [EEP00] The RDA for average males is 130g/day. [RDI05] Since typical adult males need 2,000kcal/day. This is consistently with my one third recommendation.
The minimum fat intake is not that well-established. Some sources claim that only essential fatty acids is needed. If this is the case, the RDA for adult males is 17g/day Omega-6 fatty acid and 1.6g/day Omega-3 fatty acid. [RDI05] This is about 8.5% of daily needs. We might also need some other fats but most likely we can get them from our abundant fat store. Therefore, I think it is safe to assume the minimum fat we need to eat is 10% of our Daily Calories Needs.
Here is calculator for you to calculate the minimum protein, carb and fat intake per day if you are living a sedantary lifestyle. To obtain your body fat %, please use the calculator in the Introduction page. If you are working out in addition to dieting, please refer to the exercise pages to learn about further adjustment to the diet.
Yee Man's Scientific Fat Loss Diet Calculator: (To use it, input your body weight and your body fat percentage and then click "Calculate")
Here is a sample diet for a person at 77kg, 20% body fat percentage can look like:
| Food | Protein | Carb | Fat | Total | GI | Max. GL |
| Breakfast: Milk + Bread | 57 | 143 | 24 | 224 | N/A | 18.31 |
| Fat-free Milk (247g) | 33 | 49 | 4 | 86 | 31 | 3.80 |
| 2 High-fiber Bread Slices (56g) | 24 | 94 | 20 | 138 | 67 | 15.75 |
| Breakfast Snack: Pear | 4 | 90 | 2 | 96 | 33 | 7.42 |
| 1 Pear (165g) | 4 | 90 | 2 | 96 | 33 | 7.42 |
| Lunch: Steamed Broccoli w/ Shrimp + Rice | 150 | 291 | 23 | 474 | N/A | 40.14 |
| Broccoli (364g) | 48 | 64 | 12 | 124 | N/A | N/A |
| 8 Shrimps | 80 | 4 | 6 | 90 | N/A | N/A |
| Cooked White Rice (200g) | 22 | 223 | 5 | 260 | 72 | 40.14 |
| Lunch Snack: Apple | 5 | 139 | 5 | 149 | 40 | 13.90 |
| Apple | 5 | 139 | 5 | 149 | 40 | 13.90 |
| Dinner: Sauteed Bokchoy + Rice | 50 | 251 | 132 | 443 | N/A | 40.14 |
| Oil (14g) | 0 | 0 | 120 | 120 | N/A | N/A |
| Bokchoy (490g) | 28 | 28 | 7 | 63 | N/A | N/A |
| Cooked White Rice (200g) | 22 | 223 | 5 | 260 | 72 | 40.14 |
| Total | 266 | 914 | 186 | 1,356 | N/A | 119.91 |
This diet should allow this person to lose at most 532.47g of fat per week. There is enough protein (>246.4kcal/day) and enough carb (>680.22kcal/day), so this person won't get into Starving Mode. The actual GL for Lunch and Dinner will likely be much lower than 40.14 because the high GI rice is eaten with other food. However, I would still recommend this person to substitute white rice with brown rice and also reduce the portion of rice to minimize GL. The reduction in rice portion can also reduce the total calories and hence more fat loss.
Satiety is the feeling of fullness and disappearance of appetite after a meal. While the low calories low fat diet I proposed here looks theoretically promising, can people really sustain on this diet? One obvious problem is that you might feel hungry with this diet. If you are the strong-willed type who can endure hunger, then you can skip the entire discussion of satiety. Otherwise, read on!
Many people think that if they are hungry then they need to eat. This is not necessarily true. When your stomach is empty or near empty, your stomach secrets a hormone called ghrelin to signal hunger. You have to understand that your stomach is not a calories counter. There is no way it can count how many calories you have just consumed. It is just a container who knows whether it is full or empty.
Studies show that while people might consume nutrients in different amount every day, they do consume roughly the same volume of food every day. [NM03] This is not surprising, given that the size of our stomach is roughly fixed after we become an adult.
Therefore, as an extension to the low calories diet we derived to lose fat, a good diet should make your stomach full with minimum amount of calories. This derives our second diet rule: we should eat food that has low calories per "bulk" - by "bulk", I mean the volume of food after you chew it in your mouth and swallow it down your throat. However, in general it is hard to find nutrition data for calories per "bulk", so I suggest we go for low calories per weight diet.
An exception to this low calories per weight diet is the food that contains a lot of non-viscuous liquid content, for example, orange juice. This is because the liquid content is absorbed very quickly such that the "bulk" of your orange juice shrinks considerably in a very short period of time.
To find foods with low calories per weight, you can go to NutritionData's Nutrition Search. The nutrition data at the site is mostly constructed using the official USDA nutrient data. You can find out complete and accurate nutrient data for most food.
It is known that protein intake increases the production of a hormone called "glucagon-like petitide 1". This hormone sends satiety signal to the brain. According to a study, protein supplement can significantly reduce the occurrence of binge eating disorder. [LW04]
Protein-rich and Fat-rich food are known to be very slow to digest. Therefore it is good to have them in your meal provided that the calories they contribute is still well within your limit. Since protein only has 4 calories per gram as oppose to 9 calories per gram for fat, high-protein food is preferred based on our low calories per weight principle.
The story with carbohydrates is way more complicated. There is a widespread belief that simple carbohydrates (sugar) are absorbed in a much faster rate than complex carbohydrates (carbohydrates in beard, rice, wheat,etc). However, this is not necessarily true. The absorption rate is actually more closely related to Glycemic Index introduced previously. The lower the GI, the slower the absorption.
In general, low GI high-carb food are the vegetables and fruits. The reason being that they contain a lot of dietary fiber. Dietary fiber is the hard to digest part of high-carb food. Therefore it significantly slows down the absoprtion of nutrients. As a result, high-fiber carb-rich food is preferred.
We have now finished the discussion of various aspect of nutrients that are related to fat build-up. Let me summarize what the good foods are:
Examples of good food:
Examples of bad food:
Examples of something in between:
There are three stages in my Program. The first stage is called Investigative Stage where you will investigate your body limits that will form the basis of how you lose fat in the subsequent stages. This will last for a month or two. Next comes the Fat Loss Stage. Here you follow the plan you derived in the Investigative Stage to maximize fat loss until you reach your body fat percentage goal. The length of this stage varies but most likely at least six months. The Final Stage is Fat Loss Maintenance Stage. You reach your body fat goal. So now you adjust your diet and/or exercise level such that you don't lose or gain fat and you can now enjoy your new found body!
Having outlined the Program for you, I am going to get into the gory details.
First, in the Investigative Stage, you should measure your body fat percentage and body weight every day when you wake up in the morning. This will help you track your fat loss progress. Then gradually reduce the amount of food you eat. For example, in my case, I used to eat 5/4 cup of rice per meal. I reduced it first to 1/2 cup for a week, then 3/8 cup the next and finally 1/4 cup.
At the same time, you substitute the bad food (high calories per weight, low fiber, high GI) you used to eat with good food (low calories per weight, high fiber, low GI). Combined with increased level of cardio exercise and/or weight training.
After a week, you check how much body fat is lost (body weight times body fat % gives you your body fat weight). If you find that you feel weak or depressed, that means you either overtrain or undereat. You can correct it by eating more or workout less. If you find that your fat losing rate is way slower than is predicted with my Scientific Fat Loss Diet Calculator, you can eat less or workout more. and see if you can make better progress.
For those of you who wants to be more precise and wouldn't mind counting calories, you can count the calories you had for the week using the Nutrition Data website. Then you can contruct a Calories Breakdown Table for yourself and see how you can improve your diet.
After many weeks of trial and errors, now you have found the sweet spot of calories intake and exercise level to lose fat. Keep this up and get ready for the second stage!
Next, comes the Fat Loss Stage. Keep doing what you have been doing at the end of your Investigative Stage until you reach your body fat percentage goal. This might take a while. For example, if I have sedantary lifestyle at 77kg body weight and 20% body fat, I will have a Daily Calories Needs at 2,040.67kcal/day. If I opt for the 1,356kcal/day diet as descrbied in the table, then I can lose at most 76.07g/day of fat per day. To get to 10% body fat, it will take me at least 101.22 days!
Congratulations! Finally you reach your body fat percentage goal. From now on, your job will be to maintain your fat. This can be done by gradually eating more and/or working less. If you choose to eat more, you canmake up the deficit by eating more carb and/or fat, e.g. eat more vegetables but not fruits or starch-rich food or eat more meat (preferably fatty fish like Salmon, Tuna, etc). If you are more sensitive to insulin, you can chooose to have more fat instead of carb. Another good fat you can have is Medium Chain Triglycerides (MCTs). They are shorter fats that can enter mitochondira to be oxidized directly such that most of them are not stored (ie won't make you fat) but it also has no effect on insulin. You can get it naturally from Coconut Oil or Palm Kernel Oil.
While my diet seems scientifically sound, there are still holes in it that I am still in the process of doing more research. There are at least two:
Hopefully, I will find the answers to these questions as soon as possible. Meanwhile, if you find any logical errors or if there are any statements that contradicts some mainstream textbooks and papers published in reputed academic journals, please let me know and I will take a look.
Thank you very much for reading! Happy Fat Loss! :)