Authors: Chris Kresser
Tags: #Health & Fitness / Diet & Nutrition / Diets, #Health & Fitness / Diet & Nutrition / Weight Loss
Measure
: 1 cup, cubes
Carbohydrate, G
: 12
Vegetable
: Collard greens
Measure
: 1 cup, chopped
Carbohydrate, G
: 11
Vegetable
: Romaine lettuce (raw)
Measure
: 1/2 head
Carbohydrate, G
: 10
Vegetable
: Green beans, snap
Measure
: 1 cup
Carbohydrate, G
: 10
Vegetable
: Red pepper
Measure
: 1 cup, strips
Carbohydrate, G
: 9
Vegetable
: Onion
Measure
: 1 medium
Carbohydrate, G
: 9
Vegetable
: Mushrooms, white
Measure
: 1 cup, pieces
Carbohydrate, G
: 8
Vegetable
: Turnip
Measure
: 1 cup, cubes
Carbohydrate, G
: 8
Vegetable
: Beets
Measure
: 1/2 cup, slices
Carbohydrate, G
: 8
Vegetable
: Kale
Measure
: 1 cup, chopped
Carbohydrate, G
: 7
Vegetable
: Peas
Measure
: 1/4 cup
Carbohydrate, G
: 7
Vegetable
: Broccoli
Measure
: 1 cup, chopped
Carbohydrate, G
: 6
Vegetable
: Carrots (raw)
Measure
: 1 medium
Carbohydrate, G
: 6
Vegetable
: Zucchini
Measure
: 1 cup, sliced
Carbohydrate, G
: 5
Vegetable
: Cauliflower
Measure
: 1 cup (1-inch pieces)
Carbohydrate, G
: 5
Vegetable
: Asparagus
Measure
: 4 spears
Carbohydrate, G
: 2
I recommend consuming as many nonstarchy vegetables during the day as you like but
not counting them toward your total carbohydrate intake
.
Your optimal intake of nonstarchy vegetables will depend on digestive function (some of them are high in insoluble fiber, which can be hard on an inflamed gut) and personal preference, but approximately one pound per day is a good target for most people.
Fruits contain a mixture of glucose and fructose. They also contain a wide range of micronutrients and are a good source of fiber (mostly soluble). Along with starchy plants (see next section), fruits should be a primary source of carbohydrates in your diet.
Fruit
: Banana
Measure
: 1 medium
Carbohydrate, G
: 27
Fruit
: Pear
Measure
: 1 fruit, medium
Carbohydrate, G
: 27
Fruit
: Pomegranate
Measure
: 1/2 fruit (4-inch piece)
Carbohydrate, G
: 27
Fruit
: Mango
Measure
: 1 cup, pieces
Carbohydrate, G
: 25
Fruit
: Apple
Measure
: 1 fruit (3-inch piece)
Carbohydrate, G
: 25
Fruit
: Pineapple
Measure
: 1 cup, chunks
Carbohydrate, G
: 22
Fruit
: Orange
Measure
: 1 fruit (3-inch piece)
Carbohydrate, G
: 18
Fruit
: Grapes
Measure
: 1 cup
Carbohydrate, G
: 16
Fruit
: Papaya
Measure
: 1 cup, 1-inch pieces
Carbohydrate, G
: 16
Fruit
: Peach
Measure
: 1 medium (2 2/3 inch)
Carbohydrate, G
: 14
Fruit
: Cantaloupe
Measure
: 1 cup, cubes
Carbohydrate, G
: 13
Fruit
: Strawberries
Measure
: 1 cup, halves
Carbohydrate, G
: 12
Fruit
: Watermelon
Measure
: 1 cup, diced
Carbohydrate, G
: 12
Fruit
: Blueberries
Measure
: 1/2 cup
Carbohydrate, G
: 11
Fruit
: Raspberries
Measure
: 1/2 cup
Carbohydrate, G
: 8
Fruit
: Plum
Measure
: 1 fruit (2 1/8 inch)
Carbohydrate, G
: 8
Fruit
: Tomato
Measure
: 1 cup, chopped
Carbohydrate, G
:7
Those with insulin resistance, diabetes, or metabolic syndrome may see improvements by restricting fruit intake to one to two servings a day and by choosing fruits that are lower in sugar, like berries and melon. See
chapter 18
for more on how to determine your optimal carbohydrate intake.
Starchy plants include tubers like potatoes and sweet potatoes, roots like taro and yuca, and fruits like plantain and breadfruit. They are primarily broken down into glucose and are thus well absorbed by most people. There are a few caveats to this, however:
•
Though all humans produce amylase (the enzyme that breaks down starch), some produce less of it than others and as a result may not tolerate starch as well.
•
The intestinal bacteria feed on starch. This is generally a good thing. However, when there’s an overgrowth of bacteria in the small intestine (as is often the case with digestive conditions like GERD and irritable bowel syndrome), starch may worsen the problem and cause gas, bloating, and changes in stool frequency.
•
Those with diabetes, impaired glucose tolerance, or other problems with blood-sugar regulation may find that starch aggravates the condition.
The key, as always, is to experiment. I have patients with digestive and blood-sugar issues who are able to tolerate moderate amounts of starch without a problem.
Ron, forty-six, came to see me complaining of constipation. He averaged only two to three bowel movements per week, and even those were not complete evacuations. His abdomen was bloated and tense most of the time, and his wife constantly complained about his bad breath.
While reviewing Ron’s case history, I noticed that he had been on a very low-carb diet for several years. He told me that he wasn’t constipated before going low-carb, but he had lost twenty-five pounds on the diet so he had stuck with it over the years. I asked Ron to add some starchy plants, like potatoes, sweet potatoes, taro, plantains, and yuca, back into his diet. I explained that these foods were high in fermentable fibers that feed healthy gut bacteria and that constipation is often caused by an imbalance of good and bad bacteria in the gut.
Ron was concerned about adding these foods back into his diet because of their carbohydrate content. He told me he’d been on a low-fat, high-carb diet prior to switching to low-carb, and he felt the high-carb intake had contributed to his weight gain. However, the carbs Ron was eating prior to going low-carb were almost all processed and refined. I explained to Ron that starchy plants are not only lower in carbohydrates than grain flours and sugar but higher in nutrients and less likely to promote overeating.
Within a few weeks of adding starch back into his diet, Ron began having a complete, daily bowel movement. His energy and sleep also improved, and despite his concern about gaining weight, he actually lost a few pounds.
I’ve listed several different starchy plants in the following list. If you can’t find some of these at your local supermarket, check out ethnic markets in your area. You can often find taro and lotus root at Asian markets, for example, and yuca and plantains at Latin markets. You can make
great fries with yuca and great chips with taro, especially if you roast them in duck fat or lard. See
chapter 21
for recipes.
Starchy Plant
: Potato, russet
Measure
: 1 large
Carbohydrate, G
: 64
Starchy Plant
: Tapioca
Measure
: 1/2 cup
Carbohydrate, G
: 63
Starchy Plant
: Plantain
Measure
: 1 cup, slices
Carbohydrate, G
: 48
Starchy Plant
: Taro
Measure
: 1 cup, sliced
Carbohydrate, G
: 46
Starchy Plant
: Yuca
*
(aka manioc, cassava)
Measure
: 1/2 cup
Carbohydrate, G
: 39
Starchy Plant
: Sweet potato
Measure
: 1 large
Carbohydrate, G
: 37
Starchy Plant
: Yam
Measure
: 1 cup, cubes
Carbohydrate, G
: 37
Starchy Plant
: Breadfruit
Measure
: 1/2 cup
Carbohydrate, G
: 30
Starchy Plant
: Acorn squash
Measure
: 1 cup, cubes
Carbohydrate, G
: 30
Starchy Plant
: Butternut squash
Measure
: 1 cup, cubes
Carbohydrate, G
: 22
Starchy Plant
: Lotus root
Measure
: 10 slices
Carbohydrate, G
: 14
Your optimal intake of starchy plants will depend on several factors, which we’ll explore in more detail in
chapter 18
. As a starting place, I’d recommend about one pound per day. That comes out to roughly two to four servings of starchy plants per day.
•
Most people should aim to get between 15 and 30 percent of their total daily calories from carbohydrates. If you have blood-sugar issues or are trying to lose significant amounts of weight, aim for between 10 and 15 percent of total calories.
•
Eat as many nonstarchy vegetables as you’d like throughout the day. How much you eat depends largely on personal preference and how well you digest them, because they don’t make a significant contribution to total carbohydrate intake.
•
Eat approximately two to five servings of fruit per day. If you have a blood-sugar issue or are trying to lose weight, aim for the lower end of the range and choose low-sugar fruits, like berries and melon. If you’re lean, active, and have no blood-sugar issues, aim for the higher end of the range.
•
Eat approximately two to four servings of starchy plants per day. If you’re restricting carbs, eat fewer servings and smaller amounts of each serving.
•
Avoid grains, concentrated sweeteners, and dairy products as carbohydrate sources during the Step 1 Reset. You’ll have a chance to reintroduce some of these if you choose during Step 2.
•
Avoid fortified fiber products and most fiber supplements. Soluble fiber or prebiotic supplements may be useful in some situations, which we’ll discuss in later chapters.
Notes for this chapter may be found at ChrisKresser.com/ppcnotes/#ch6.
The great thing about protein, an essential nutrient for humans, is that most of us naturally eat the right amount of it without paying much attention. Our brains strongly influence our desire to consume it, based on how much our bodies need. You are probably very familiar with animal sources of protein (like meat and dairy) and plant sources as well (like soybeans). As with fats and carbohydrates, the quality of proteins—and what they do in your body once they are consumed—differs considerably, as you’ll soon see.
Protein is vital to life because it is the building block of all body tissues; it can also be converted into glucose for energy. Protein molecules are composed of individual amino acids linked together in a chain. Amino acids can be divided into three categories: essential, nonessential, and conditional. Essential amino acids can’t be produced by the body and must be obtained from the diet. Nonessential amino acids can be synthesized from essential amino acids or by breaking down proteins during digestion. Conditional amino acids are usually nonessential but can be essential in certain situations (for example, in times of chronic illness or stress).
There are two things to consider with protein: how much you should eat, and what type. I’ll cover
how much
protein each person should eat in
chapter 18, where we’ll discuss further refining the diet for your particular circumstances. In this chapter we’re going to focus more on what
types
of protein are optimal for human nutrition. The factors that determine protein quality include:
•
Amino acid profile.
Complete proteins contain all essential amino acids, whereas incomplete proteins are lacking in one or more essential amino acids.
•
Bioavailability.
No matter how much protein a food has, if you can’t digest and absorb it, it won’t benefit you.
•
Toxicity.
Some proteins are more likely than others to cause an immune response or allergic reaction.
The best proteins are those that contain all essential amino acids in a bioavailable form and have a low potential for toxicity
.
Over the years, several different methods have been used to measure protein quality. While these methods provide useful information, each of them has significant shortcomings:
•
Protein efficiency ratio (PER).
Protein efficiency ratio determines the effectiveness of a protein by measuring how much weight an animal (usually a rat) gains after being fed a test protein. The problem is that the effects of a given protein on growth in rats doesn’t necessarily correlate with its effects on growth in humans.
•
Biological value (BV).
Biological value measures how efficiently the body utilizes a protein consumed in the diet. A food with a high BV indicates a strong profile of essential amino acids. BV is limited in its usefulness, however, because it does not take into account several key factors that influence how protein is digested and absorbed.
•
Net protein utilization (NPU).
Net protein utilization is similar to BV, but it measures the retention of absorbed nitrogen more directly (nitrogen is a by-product of protein metabolism). NPU has the same shortcomings as BV.
To address these shortcomings, the Food and Agriculture Organization of the United Nations World Health Organization created a measure of protein quality called the protein digestibility–corrected amino acid score (PDCAAS). This method combines the amino acid profile of the protein (whether it’s complete or incomplete) with the true fecal digestibility of the protein (how much of the protein is actually absorbed). PDCAAS values are expressed on a scale of 0 to 1, with 1 being the highest. This scoring method has been the preferred method for measuring protein value in scientific studies since it was introduced in 1989.
The information below lists the PDCAAS of some common animal and plant proteins.
Protein Type
: Casein
Protein Digestibility–corrected Amino Acid Score
: 1.00
Protein Type
: Egg
Protein Digestibility–corrected Amino Acid Score
: 1.00
Protein Type
: Milk (casein and whey)
Protein Digestibility–corrected Amino Acid Score
: 1.00
Protein Type
: Whey protein
Protein Digestibility–corrected Amino Acid Score
: 1.00
Protein Type
: Chicken (light meat)
Protein Digestibility–corrected Amino Acid Score
: 1.00
Protein Type
: Turkey (ground)
Protein Digestibility–corrected Amino Acid Score
: 0.97
Protein Type
: Fish
Protein Digestibility–corrected Amino Acid Score
: 0.96
Protein Type
: Beef
Protein Digestibility–corrected Amino Acid Score
: 0.92
Protein Type
: Soybeans
Protein Digestibility–corrected Amino Acid Score
: 0.91
Protein Type
: Chickpeas
Protein Digestibility–corrected Amino Acid Score
: 0.78
Protein Type
: Black beans
Protein Digestibility–corrected Amino Acid Score
: 0.75
Protein Type
: Vegetables
Protein Digestibility–corrected Amino Acid Score
: 0.73
Protein Type
: Legumes (average)
Protein Digestibility–corrected Amino Acid Score
: 0.70
Protein Type
: Kidney beans
Protein Digestibility–corrected Amino Acid Score
: 0.68
Protein Type
: Fruits
Protein Digestibility–corrected Amino Acid Score
: 0.64
Protein Type
: Rolled oats
Protein Digestibility–corrected Amino Acid Score
: 0.57
Protein Type
: Lentils
Protein Digestibility–corrected Amino Acid Score
: 0.52
Protein Type
: Peanuts
Protein Digestibility–corrected Amino Acid Score
: 0.52
Protein Type
: Tree nuts
Protein Digestibility–corrected Amino Acid Score
: 0.42
Protein Type
: Whole wheat
Protein Digestibility–corrected Amino Acid Score
: 0.40
Protein Type
: Wheat gluten
Protein Digestibility–corrected Amino Acid Score
: 0.25
As you can see, without exception, animal proteins are of higher quality than plant proteins like legumes, grains, fruits, and vegetables. It would appear that soybeans are nearly as high quality a protein as beef.
However, although the PDCAAS is the most accepted method of measuring protein quality, one of its shortcomings is that it does not take antinutrients into consideration. Soy contains substances that have been shown to decrease protein absorption in the small intestine. These antinutrients are also present in other legumes (such as lentils and kidney beans) and cereal grains (such as wheat, corn, oats), and they’ve been shown to decrease assimilation of amino acids in these foods by as much as 50 percent. If the PDCAAS took this data into account, the scores for soy protein, other legumes, and cereal grains would be significantly lower than those listed in the list above.
It’s clear that animal protein is superior to plant protein in terms of amino acid composition and bioavailability. But within the animal-protein
category, some foods have more proteins than others. For those wishing to boost their protein intake (I’ll discuss who might fall into this category in later chapters), it’s helpful to know which animal products are the most concentrated protein sources. The information below lists the protein content of various animal foods based on a typical serving size.
Food
: Duck
Measure
: 1/2 duck
Protein, G
: 52
Food
: Sockeye salmon
Measure
: 1/2 fillet
Protein, G
: 43
Food
: Halibut
Measure
: 1/2 fillet
Protein, G
: 36
Food
: Rockfish
Measure
: 1 fillet
Protein, G
: 33
Food
: Tuna salad
Measure
: 1 cup
Protein, G
: 33
Food
: Beef, bottom round
Measure
: 3 oz.
Protein, G
: 30
Food
: Chicken, light meat
Measure
: 3 oz.
Protein, G
: 28
Food
: Lamb loin
Measure
: 3 oz.
Protein, G
: 26
Food
: Beef sirloin
Measure
: 3 oz.
Protein, G
: 25
Food
: Ham
Measure
: 3 oz.
Protein, G
: 25
Food
: Swordfish
Measure
: 1 piece
Protein, G
: 25
Food
: Yellowfin tuna
Measure
: 3 oz.
Protein, G
: 25
Food
: Pork spareribs
Measure
: 3 oz.
Protein, G
: 25
Food
: Chicken, dark meat
Measure
: 3 oz.
Protein, G
: 24
Food
: Turkey, light meat
Measure
: 3 oz.
Protein, G
: 23
Food
: Cottage cheese
Measure
: ½ cup
Protein, G
: 14
Food
: Yogurt, whole milk
Measure
: 1 cup
Protein, G
: 8
Food
: Milk, whole
Measure
: 1 cup
Protein, G
: 8
Food
: Swiss cheese
Measure
: 1 oz.
Protein, G
: 8
Food
: Egg, whole
Measure
: 1 extra large
Protein, G
: 7
As you can see, seafood, poultry, and red meat are the most concentrated sources of protein. While dairy and egg proteins score highest on the PDCAAS, they are generally much lower in protein per serving than fish and meat.
Emily, age thirty-two, came to see me complaining of severe fatigue. She could hardly get up in the morning, and she crashed in the afternoons. Up until about six months before our visit, she had been a competitive cyclist, but she had stopped competing because her performance and ability to recover after races and workouts had declined so rapidly. She began to notice extra fat around her waist and in her thighs for the first time in her life. She also had dark circles under her eyes, and her hair was falling out.
“I feel like I’ve aged about twenty-five years in the past two years,” she told me. “I’m scared that I won’t be able to ride again, and that this will just get worse.” She had become a vegan about two years earlier. (She had been eating a standard American diet prior to going vegan.) At first she felt fantastic, and her performance and energy levels actually improved. But after about nine months she noticed some fatigue and a decline in her performance. She was also hungry
all the time, and despite eating every two to three hours, she never felt fully satisfied. As time progressed her symptoms worsened and she decided to get help.
I explained to Emily that vegan diets were low in bioavailable, complete proteins. While on paper, it’s possible to get enough protein by eating legumes, grains, and soy products, those proteins are not well absorbed or are lacking in essential amino acids. As she was a competitive athlete, her needs for highly digestible, complete protein were even higher than the average person’s, which is why she was feeling so poorly.
After a lot of consideration, Emily decided to begin eating eggs, fish, and chicken again. Almost immediately she noticed an improvement in her energy and sense of well-being. Within a month she was back on her bike and training, and within three months she was ready to start competing again. Her extra body fat melted away, her hair stopped falling out, and the dark circles under her eyes disappeared.
•
Eat the amount of protein you crave. Most people naturally eat the right amount because the brain strongly influences the craving for it depending on how much is needed. In
chapter 18
we will discuss optimizing protein intake based on your individual circumstances.
•
Meat, poultry, seafood, and eggs should form the bulk of your protein intake during the Step 1 Reset.
•
Dairy products are also a source of high-quality protein and may be reintroduced during Step 2 to determine whether you tolerate them.
•
Fruits, vegetables, nuts, and seeds are good sources of micronutrients but are low in absorbable protein.
•
Grains and legumes are poor sources of protein compared to animal products. They also contain antinutrients that reduce the
absorption of amino acids, as well as proteins that may provoke an immune response. That said, moderate amounts of certain grains and legumes may be tolerated when special steps are taken to reduce their toxicity, and some may wish to reintroduce these during Step 2.