Protein diet composition

Protein diet composition

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I have read that non veg food are better for proteins while veg food is deficient in either one or other protein. If it is so are herbivores protein deficient always in case of animals as well as humans?

Link from VonBeche is good.
Proteins vary in amino acid content. Humans can make some but we need 9 of them in our diets.

from Nine amino acids-histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine-are not synthesized by mammals and are therefore dietarily essential or indispensable nutrients.

This guy is clearly a vegetable enthusiast but he makes a good point (and provides a nice table): just about any vegetable can provide enough amino acids if you eat enough of it. Getting your entire caloric requirement from iceberg lettuce would a project, it is true. But until I did the back reading for this answer I thought it would be impossible to take in the calories it would require to get all necessary amino acids from some of these plant foods. Thanks michaelbluejay.

I here assert that animal foods have more amino acids per calorie than vegetable foods. So, if you wanted to limit calories but meet your amino acid requirement it would be easier to do with animal proteins than with vegetable proteins.

But even all calories from potatoes can get you your amino acids. The people who get into trouble are people who are not getting all the calories they need because they are starving, and the calories they do get are from low protein source foods like yams or bananas. That is protein-calorie malnutrition.

Proteins: Composition and Structure | Macromolecules

Peptide bond is produced when carboxyl radical of one amino acid reacts with the amino (-NH2) group of the other amino acid. The basic structural formula of amino acids is shown in Fig. 4.1.

It consists of one alpha (a) carbon atom that is associated with an amino group (-NH2) with a potential (+) charge, a carboxyl group with a (-) charge, a hydrogen atom and a side chain “R” that varies in the different amino acids.

There are usually 20 amino acids found in proteins (for structural formulae of the amino acids, any book of biochemistry may be consulted). These twenty amino-acids are divided into 7 groups (Table 4.1). All the 20 amino acids need not be present in a given protein.

The side chains (R) of amino acids are responsible for the different properties, such as, water solubility, interaction with other amino acids etc. of the amino acids. The amino acids possessing -CH3 group are much less soluble in water and they are called “hydrophobic” amino acids, e.g., leucine, isoleucine, valine.

The amino acids that are water soluble are called “hydrophilic” amino-acids, e.g., lysine (+ charge) and aspartic acid (-charge). The sulfhydryl group (-SH) of cysteine can interact with the -SH group of other cysteine in the protein chain to make a disulfide linkage (S-S). The H atoms of hydroxyl group (-OH) or carboxyl group of the “R ‘ chain can make hydrogen bonding with other amino acids in the protein chain. The bonds are required for stabilizing the structure of protein molecules.

Structure of Proteins:

The protein molecule containing a single polypeptide chain (monomeric protein) can take primary, secondary and tertiary structures. The protein composed of two or more polypeptide chains (multimeric proteins) can take one more degree of conformation, the “quaternary structure”.

Primary Structure:

Proteins are long polypeptide chains. One end of their chain contains the free amino group (-NH2), while the other end contains the free carboxyl group . The amino acids of the chain are linked with peptide bonds .

Number of amino acids and their sequence varies in different types of proteins. Because the sequence and number of amino acids in the proteins are determined by the information contained in the gene encoding them, the primary structure of proteins can be compared with the base sequence of the concerned nucleic acid as follows.

(1) Proteins are polypeptides made of linked amino acids, whereas nucleic acids are poly­nucleotides made of ribonucleotides (RNA) and deoxyribonucleotides (DNA).

(2) Proteins contain -NH2 group at one end and group at the other end, whereas nucleic acids contain phosphoric acid at one end (5′-end) and -OH group at the other end (3′-end).

(3) Amino acids are linked by peptide bonds in proteins whereas nucleotides are linked by phosphodiester bonds (-O-P-O) in nucleic acids.

Secondary Structure:

The secondary structure of proteins occurs due to the formation of non-covalent H-bonds between -NH and -CO groups of the amino acids which are very close to each other. Most of the proteins are coiled into a right-handed helix called the “alpha helix”. Other types of secondary structure are “beta pleated sheet” where polypeptide chains lie side by side, stabilized by H-bonds.

Tertiary Stricture:

Polypeptide chain bends and folds at various places to produce some spherical conformation. The structure is stabilized by side chain of amino acids. The sites of specificity of enzymes are formed due to tertiary structure.

Quaternary Structure:

Some proteins exist as association of two or more polypeptide chains. Differed polypeptide chains are bound together by non-covalent and occasionally by covalent bonds. For example, a complete human hemoglobin molecule consists of four individual polypeptide chains, two identical alpha (α) chains and two identical beta (β) chains.

The individual a chains consist of 140 amino acids and the individual β chains consist of 146 amino acids. The core enzyme of RNA polymerase is composed of 5 polypeptide chains, β’ βα2ω.

Protein synthesis occurs under the direction of information stored in DNA as “codes”. Different kinds of RNAs, such as ribosomal RNA, transfer RNA and messenger RNA are produced on DNA template through the process of “transcription”.

Protein synthesis occurs on ribosomes where tRNA, brings amino acids to form polypeptide, according to the “codon’ in the mRNA thus the message from DNA is translated into a protein. Different components of protein synthesis are described in the following sections.


Behavioural ecologists increasingly focus on why individuals differ in average behaviour (i.e., why there is among-individual variation or ‘animal personality’) and behavioural plasticity (i.e., why within-individual variation or ‘behavioural stability’ differs among individuals) [1–3]. Quantitative genetics studies imply that, on average, 50% of this individual variation in behaviour is due to additive genetic effects (reviewed in [4]). Environmental factors that permanently affect the phenotype therefore likely play an equally important role in shaping individual behaviour. Indeed, various studies have experimentally demonstrated the importance of the early-life environment in permanently shaping behavioural phenotypes [5–9]. For example, studies on birds imply that food availability during early-life can shape both aggressiveness and exploratory tendency in adulthood [10].

Empirical studies increasingly quantify the contribution of among- and within-individual variation in shaping phenotypic variation observed in animal behaviour [3, 11]. Recent research indicates that the (relative) magnitudes of these two variance components can show sex-specificity and spatiotemporal variation within a single species [12–17]. This is in line with quantitative genetics studies showing that the expression of genetic variance is often a function of the environment [18]. For example, the additive genetic variance may either increase, or decrease, under more favourable (or less ‘stressful’) conditions [19, 20]. Behavioural examples are relatively few but include work on the house cricket (Acheta domesticus) showing that low quality diet increases within-individual stability in anti-predatory behaviour, and consequently increases its repeatability [16]. Similarly, adults of the western trilling crickets (Gryllus integer) exposed to bacterial pathogens during ontogeny are less repeatable (due to decreased among-individual variance) in boldness compared to controls [15]. Examples of environment-specific within-individual variation, furthermore, include work on red-winged blackbirds (Agelaius phoeniceus), where females decrease their within-individual variance in nestling provisioning effort with increasing nestling age [17], studies on hermit crabs (Pagurus bernhardus), where individuals increase their level of within-individual behavioural variability when faced with increased perceived predation risk [13], and studies on zebra finches (Taeniopygia guttata), where early dietary restriction decreases the amount of within-individual variance in general activity [14].

Here we propose that the nutritional environment represents a key environmental factor determining the development and expression of behaviour, thus shaping personality and level of behavioural stability [21]. We further propose that there are three components of behaviour that can be affected by nutritional history. First, average level of behaviour may vary among individuals with different nutritional histories (represented by the dotted line in Fig. 1). Indeed, previous studies have demonstrated that poor nutrition can impair behavioural development and provide reliable cues to the expression of later behaviour [14, 22–28].

Schematic representation of how mean level, and within- and among individual variances were expected to differ between environments. Each dot with vertical line represents one theoretical individual. The black line represents the extent of variation in behaviour that is observed across observations of a single individual (i.e., within-individual variance, VR). The change in the length of black lines indicates the change in within-individual variance (VR) across environments. The variation among dots represents the variation among individuals in average phenotype (i.e., among-individual variance, VI). The dashed line indicates a change in population-level mean

Second, the extent of individual differentiation (i.e., the amount of among-individual variance VI) may differ among groups of individuals differing in nutritional history (variance component VI in Fig. 1). For example, under high-quality dietary conditions (characterized by abundant resources or balanced nutrients), multiple strategies with equal fitness payoffs may exist by which resources are allocated among costly behaviours, while this might not be the case under low-quality conditions. If so, one would expect the among-individual variance in behaviour to be increased under high-quality dietary conditions [21] (Fig. 1). One may, by contrast, also expect the opposite pattern, for example, when low-quality dietary environments represent relatively novel environmental conditions where additional (‘cryptic’) genetic variance is expressed [29], leading to decreased among-individual variance under high-quality dietary conditions (e.g., [14, 30, 31]).

Third, behavioural instability (i.e., the amount of residual within-individual variance VR) may also differ between individuals subjected to different nutritional histories (variance component VR in Fig. 1). Owing to the costs associated with phenotypic plasticity [32], for example, only individuals experiencing high-quality nutritional environments might be able to invest in the sensory and processing apparatus necessary for expressing adaptive phenotypic plasticity. High-quality nutritional environments during development might therefore enable individuals to more flexibly respond to micro-environmental variation experienced during adulthood. For example, individuals subjected to high-quality nutritional environments during development might develop the capabilities to adjust their level of aggressiveness in response to changes in their social environment, whereas individuals with a low-quality dietary past might remain less flexible [33, 34]. This multitude of possible effects on behavioural variance components may thereby result in behavioural repeatabilities that vary between treatment groups [14, 28]. Importantly, as variances often increase as a function of the mean [35], effects of diet on mean behavioural phenotype are likely coupled with those on variance components (as illustrated in Fig. 1).

We further predict that effects of diet should differ between sexes and life stages. Sex-differences in sensitivity towards nutrient deficiency are expected because males and females often differ in their nutritional preference [26, 36–39]. In addition, as nutritional requirements typically change throughout an individual’s life time [40], diets experienced during early vs. late life are predicted to additively or interactively affect the expression of phenotypes in adulthood (e.g. [41–44]). In the butterfly Harmonia axyridis, for example, females raised on a poor diet during adulthood showed decreased fecundity only when not having experienced a poor diet as a larvae [42].

Here, we assessed how nutritional environments experienced during juvenile and adult life affected various behaviours and their variance components in males and females of the Southern field cricket (G. bimaculatus). Field crickets are well suited for testing the role of the nutritional environment in shaping personality and plasticity. Previous research on crickets has, for example, shown that the carbohydrate:protein (C:P) ratio of a diet affects the expression of morphology and reproductive behaviours [22, 25, 26, 44–46]. This is not surprising as protein is required for somatic development of nymphs, and eggs produced by females. Similarly, carbohydrate is needed to fuel general activity and male courtship behaviour. In our experiments, we therefore manipulated diets. We used a two-way factorial design with two juvenile diets (high-carbohydrate versus high-protein) and two adult diets (high-carbohydrate versus high-protein), and measured the expression of multiple behavioural (exploration, aggression and mating activity) and morphological (body weight and lipid mass) traits. Given the documented strong effects of the carbohydrate:protein (C:P) ratios on various key phenotypic traits [22, 25, 26, 44–46], dietary environments are generally predicted to alter body weight and the expression of behaviour, though we appreciate that such effects may also interact with social and non-social environmental factors, such as the amount of competition for resources or mates. Moreover, effects of diet on the expression of variance components (i.e., among- or within-individual variances) may also affect behavioural repeatability. We thus measured 1) nutritional preferences of juveniles, adult males and adult females and 2) nutritional intakes of juveniles and adults faced with imbalanced diets (namely, high-carbohydrate diets vs. high-protein diets, detailed below) (experiment 1). We then assessed whether 3) population-level mean trait values, 4) variance components and 5) repeatabilities differed across nutritional environments (experiment 2). We also tested 6) whether the effects of diet (on mean and variance components) differed across the sexes.

High-protein diet during gestation and lactation affects mammary gland mRNA abundance, milk composition and pre-weaning litter growth in mice

We evaluated the effect of a high-protein diet (HP) on pregnancy, lactational and rearing success in mice. At the time of mating, females were randomly assigned to isoenergetic diets with HP (40% w/w) or control protein levels (C 20%). After parturition, half of the dams were fed the other diet throughout lactation resulting in four dietary groups: CC (C diet during gestation and lactation), CHP (C diet during gestation and HP diet during lactation), HPC (HP diet during gestation and C diet during lactation) and HPHP (HP diet during gestation and lactation). Maternal and offspring body mass was monitored. Measurements of maternal mammary gland (MG), kidney and abdominal fat pad masses, MG histology and MG mRNA abundance, as well as milk composition were taken at selected time points. HP diet decreased abdominal fat and increased kidney mass of lactating dams. Litter mass at birth was lower in HP than in C dams (14.8 v. 16.8 g). Dams fed an HP diet during lactation showed 5% less food intake (10.4 v. 10.9 g/day) and lower body and MG mass. On day 14 of lactation, the proportion of MG parenchyma was lower in dams fed an HP diet during gestation as compared to dams fed a C diet (64.8% v. 75.8%). Abundance of MG α-lactalbumin, β-casein, whey acidic protein, xanthine oxidoreductase mRNA at mid-lactation was decreased in all groups receiving an HP diet either during gestation and/or lactation. Milk lactose content was lower in dams fed an HP diet during lactation compared to dams fed a C diet (1.6% v. 2.0%). On days 14, 18 and 21 of lactation total litter mass was lower in litters of dams fed an HP diet during lactation, and the pups' relative kidney mass was greater than in litters suckled by dams receiving a C diet. These findings indicate that excess protein intake in reproducing mice has adverse effects on offspring early in their postnatal growth as a consequence of impaired lactational function.

3. Disorders of Renal Function

Low fluid intake and excessive intake of protein are important risk factors for kidney stones [3]. Protein ingestion increases renal acid excretion, and acid loads, in turn, may be buffered in part by bone, which releases calcium to be excreted by the kidney. This protein-induced hypercalciuria could lead to the formation of calcium kidney stones [4]. Furthermore, animal protein is also the major dietary source of purines, the precursors of uric acid. Excessive intake of animal protein is therefore associated with hyperuricosuria, a condition present in some uric acid stone formers [5]. Uric acid solubility is largely determined by the urinary pH. As the pH falls below 5.5 to 6.0, the solubility of uric acid decreases, and uric acid precipitates, even if hyperuricosuria is not present [5]. The pathobiochemical mechanisms of animal protein-induced nephrolithiasis are shown in Figure 1 . An interesting study on the effects of protein overload on stone-forming propensity showed that consumption of high-protein diet for 6 weeks delivers a marked acid load to the kidney and increases the risk for stone formation (urinary citrate levels decreased, and urinary saturation of undissociated uric acid increased) [11]. Furthermore, in a study of three 12-day dietary periods during which the diet of the subjects contained vegetable protein, vegetable and egg protein, or animal protein, it was found that the animal protein-rich diet was associated with the highest excretion of undissociated uric acid due to the reduction in urinary pH [16]. Moreover, citrate excretion was reduced because of the acid load, and urinary crystallization studies revealed that the animal protein diet conferred an increased risk for uric acid stones [16]. In another study it was shown that a high protein intake induced changes in urinary uric acid and citrate excretion rates and a decrease in the ability of urines to inhibit calcium oxalate monohydrate crystal agglomeration [18]. The decreased ability of urines to inhibit the agglomeration of calcium oxalate crystals could provide a possible physicochemical explanation for the adverse effects of high-protein diet on renal stone formation [18]. Additionally, it has been indicated that high-protein intake could cause increased glomerular filtration rate and decreased fractional renal tubular reabsorption of calcium and urinary sodium [19]. In another study, healthy subjects with a history of renal stones fed on a low (LPD) and a high (HPD) animal protein diet after 2 weeks it was found that high dietary intake of purine-rich animal protein had an impact on urinary urate excretion and supersaturation in renal stone disease [21]. There was an increase in urinary urate, urinary acid excretion, ammonium ion excretion, and uric acid supersaturation and a fall in urine pH on HPD. The risk of forming uric acid or ammonium urate crystals or stones in the urine was increased on a high protein diet [21]. Moreover, in a prospective cohort study it was investigated whether protein intake influences the rate of renal function change over an 11-year period. The results showed that high total protein intake, particularly high intake of nondairy animal protein, may accelerate renal function decline in women with mild renal insufficiency [22]. Furthermore, a study about the short-term effect of increasing the dietary consumption of animal protein on the urinary risk factors for stone-formation showed increased levels of urinary calcium and oxalate. The accompanying increase in dietary purine caused an increase in the excretion of uric acid. The overall relative probability of forming stones, calculated from a combination of the risk factors, was markedly increased (250%) throughout the period of high animal protein ingestion [23].

Pathobiochemical mechanisms of animal protein-induced nephrolithiasis.

Building Your Meal Plan! Learn How To Calculate Protein, Carb & Fat Daily Intake For Your Goals!

(0:26)Link To Meal Planner:
(0:40)What you need to know!
(1:00)My Info & Calculations.
(2:41)Protein Multiplier.
(3:27)Fat Multiplier.
(4:12)Converting Macros from GRAMS to CALORIES.
(5:19)Carb Multiplier.
(6:41)My Daily MACROS!
(7:59)Carb Intake Guidelines.
(9:09)My FINAL Daily MACROS!
(10:22)Promo Code For FREE One Month Trial of my meal plan!
The MEAL PLAN! It seems like this topic has been blown so out of proportion, with so many different &ldquotricks&rdquo over the years, that a lot of us just say &ldquowhatever&rdquo when it comes to counting their calories and macros..
The most often words spoken are:
&ldquoI&rsquoll just east clean.&rdquo.
When it comes to reaching your goals, having a well thought out meal plan is imperative and finding the right ratios of protein, carbs, and fat is much easier than you have been lead to believe..
To begin, you will need to know the following information..
Body Fat %:
Basil Metabolic Rate BMR (Calculator Link).
At Rest:
In Motion:
For the purpose of this article, I will be using my own information as an example..
My Info:
Weight: 171 lbs.
Bodyfat %: 7% (0.07).
At Rest: 1,832 calories.
In Motion: 2,840 calories.
Once you have this information it&rsquos time to do some calculations. First, we will need to see how much of your bodyweight is FAT WEIGHT..
FAT WEIGHT = Weight x Bodyfat %.
My FAT WEIGHT: 171 lbs x 0.07 = 12 lbs.
Next we are going to use this number to find yourLEAN WEIGHT..
LEAN WEIGHT = Weight – Fat Weight.
My LEAN WEIGHT = 171 lbs – 12lbs = 159 lbs.
We will also need to find your AVERAGE BMR. This will tell us how many calories you need to burn a day in order to maintain your current bodyweight. The AVERAGE BMR is the average between your BMR In Motion and BMR At Rest. Both these numbers can be obtained on the SHF site LINK TO BMR..
AVERAGE BMR = (BMR In Motion + BMR At Rest ) / 2.
My AVERAGE BMR: (2,840 calories + 1,832 calories) / 2 = 2,336 calories.
Now let&rsquos quickly recap with all the numbers we just gathered..
My Info:
Weight: 171 lbs.
Bodyfat %: 7% (0.07).
Fat Weight: 12 lbs.
Lean Weight: 159 lbs.
BMR: 2,336 calories.
Once you have all the information you need, we are going to calculate your PROTEIN & FAT intake for the day based on your GOAL and LEAN WEIGHT..
Protein Multiplier.
This multiplier will tell you how much protein you need to ingest per day according to your goal..
Goal: Maintain / Lose Weight.
Ingest 1 gram per pound of lean weight.
My protein intake goal = 1 x 159 lbs = 159 grams.
Goal: Gain Muscle.
Ingest 1.5 grams per pound of lean weight.
My protein intake goal = 1.5 x 159 lbs = 239 grams.
Fat Multiplier.
This multiplier will tell you how much fat you need to ingest per day according to your goal..
Goal: Maintain / Lose Weight.
Ingest 0.35 grams per pound of lean weight.
My fat intake goal = 0.35 x 159lbs = 56 grams.
Goal: Gain Muscle.
Ingest 0.5 grams per pound of lean weight.
My fat intake goal = 0.5 x 159lbs = 80 grams.
My goal is to gain muscle, so I will be using the GAIN MUSCLE multipliers..
My Daily Protein & Fat Intake Goals:
Protein: 239 grams.
Fat: 80 grams.
Now that I know how much protein and fat I need to consume per day, the next step involves converting GRAMS to CALORIES. This will help me calculate how many calories are being taken by protein and fat per day and will help me determine how many calories are left over for carbohydrate intake. Below is a chart that will explain how many calories there are per 1 gram of each macronutrient..
Converting Macros from GRAMS to CALORIES.
Protein: 1 gram = 4 calories.
Carbs: 1 gram = 4 calories.
Fat: 1 gram = 9 calories.
I will now use this chart to calculate my TOTAL CALORIES being ingested from Protein & Fat..
Protein in Calories.
239 grams X 4 calories = 956 calories.
Fat in Calories.
80 grams X 9 calories = 720 calories.
Total Calories from PROTEIN & FAT.
956 calories + 720 calories = 1,676 calories.
We are now going to use this number to determine your carb intake based on your goal. But in order to do this we will need to adjust your AVERAGE BMR to reflect your goal..
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Dr. Ted Naiman to help hone higher protein options for better weight loss

We have some exciting news: Seattle family doctor and protein expert Dr. Ted Naiman is joining the Diet Doctor team.

Dr. Naiman will be helping us to help you more effectively lose weight, improve your health, and improve your body composition.

He’ll be helping you understand how to potentially leverage higher levels of protein and nutrients in your low-carb diet for better results.

“Ted is a rare kind of doctor,” says Dr. Andreas Eenfeldt, founder and CEO of Diet Doctor. “He’s extremely insightful about practical lifestyle interventions for improving health and weight. Ted knows a lot about what works and how to communicate it.”

Dr. Naiman is a clinical expert on the relationship between getting enough protein versus getting too much toxic energy from carbs and fat. He calls this relationship the protein-to-energy ratio of foods, or P:E.

“I am very excited to join Diet Doctor’s passionate and dedicated team,” says Dr. Naiman, who is the author of The P:E Diet: Leverage your biology to achieve maximum health. “What I bring is decades of real-world patient experience and a deep experience of nutrition and metabolism.”

Avid following for his insights

Dr. Naiman has some 63,000 Twitter followers for his health, fitness, and protein-to-energy insights, which include creative but simple infographics that communicate complex nutritional information.

He will be working one day a week for the company and the rest of the week continuing with his busy primary care practice in Seattle.

“What’s my particular direction and focus for Diet Doctor? It will be helping people maximize satiety per calorie using tools like protein percentage, energy density, and nutrient density,” Dr. Naiman says. 1

Those terms all relate, in general, to the quality of the protein and minerals in the food you eat compared to the excess energy — or empty calories — from carbs and fat that have no nutrient value.

By increasing the protein percentage of your food, while still keeping your carbs low, you may lose more weight, reduce your body fat, and increase lean muscle — thereby improving your body composition.

In the months ahead, Dr. Naiman will help us explain and actualize these more complex nutritional concepts in simple terms. He’ll also advise Diet Doctor on programs and meal plans to help people achieve maximum results in weight loss and health improvement.

The goal will be to help you figure out if a higher protein approach is right for you and to help you determine what level of protein you should eat, while still enjoying satisfying and delicious food.

Pioneering low-carb physician

To understand how Dr. Naiman will aid this expansion of the Diet Doctor offerings, it helps to understand Dr. Naiman’s story as a low-carb physician who has been helping patients for more than 20 years.

As detailed in an in-depth 2018 profile on Diet Doctor, Dr. Naiman trained first as an engineer and then went into medicine. He was a newly graduated medical student in 1997 when a formerly obese patient with diabetes came in for an appointment. The patient had lost more than 30 pounds and reversed his diabetes by using the low-carb Atkins diet.

This propelled him to learn everything he could about carbohydrate restriction, as well as the role of the macronutrients fat and protein, and the body’s need for various essential nutrients. He applied his engineering skills in “root cause analysis” to examine how the food we eat contributes to poor health and obesity.

Raised in a vegetarian environment, Dr. Naiman tried a low-carb diet himself and saw his health transform. Painful eczema that had plagued him since childhood went away, as did his obsessive-compulsive disorder. He greatly improved his body composition.

He began recommending low-carb or keto diets to patients more than two decades ago, making him one of the pioneering US physicians with a long track record of helping patients with the diet. He estimates he has now helped thousands of patients with a low carb or keto diet, many of whom have had extraordinary results in health improvement and weight loss.

But why did some patients stall?

Over the years, however, he noticed a recurring issue: not everyone doing a low-carb or keto diet achieved great, long-lasting success.

“I’ve seen so many patients in my practice go on keto, lose 20 pounds, get fat-adapted, feel great and then stall out super hard,” Dr. Naiman says.

Some were simply unable to lose more weight even though they had lots to lose others might even start gaining weight while still cutting out all the carbs.

Dr. Naiman realized that, when few carbs were in the diet, the culprit for stalls or poor results was usually excess fat with high energy density: butter, oils, heavy cream, fat bombs, high-fat nuts, and high-fat dairy.

When stalled-out patients started watching and reducing the excess fat (while still keeping carbs low), and increasing their consumption of satiating protein and fiber, they did not go hungry, but they did start to lose weight again.

“I’ve now had a ton of success getting patients to eat lower energy density foods by upping their protein and fiber and minimizing not only their refined carbs but their excess fats as well,” Dr. Naiman says.

What is the P:E of your food?

Through this clinical experience, his concept of the protein-to-energy ratio, or P:E, was born. This literally means: how much protein are you eating in relation to refined carbs and high-energy fats? For more success, increase the protein and fiber while decreasing carbs and fat. This increases the “satiety per calorie” and the nutrient density of your food.

Dr. Naiman recommends, wherever you are in your diet, that you try to incrementally increase your protein and fiber to see how you feel. See if that change helps you lose more weight and body fat.

Based on Dr. Naiman’s advice, Dr. EenfeIdt has been deliberately increasing his protein and fiber intake, after more than 15 years on a low-carb or keto diet. While always fit, healthy, and at a good weight, Dr. Eenfeldt was surprised when he, too, dropped more pounds, reduced his waist size and his body fat percentage, while increasing his lean muscle mass and strength. His blood pressure reduced, too.

“It’s clear, both in the research science and clinical experience, that by targeting foods that are high in protein, you end up meeting your essential nutrient needs and feeling full while eating less energy, which may help you lose weight,” Dr. Eenfeldt says.

D. Eenfeldt added, however, that “If you are doing the keto diet for epilepsy, or other neurological conditions, or are at a weight you are happy with, you can be more generous with the fat.”

Over the months ahead, Diet Doctor will help you find out if the higher protein approach is right for you as an additional option. Have no fear! Our vast array of delicious recipes will not change, we will be just adding some higher protein recipes and meal plans and helping you understand how to find out which approach is best for you.

You may notice that we will talk a bit more about protein versus energy (i.e. carbs and fat) as a percentage of calories of various foods and meals. And there may be less emphasis on added fat in recipes so that it helps you understand that fat is not a “free food” but a lever for weight loss that you can adjust based on your needs.

Dr. Eenfeldt notes that Diet Doctor is committed to constantly evaluating the science and adjusting our guidance to our members and followers in light of new information — while still helping everyone enjoy delicious, satisfying food that improves their health and helps them achieve a weight that is right for them.

We are delighted that Dr. Naiman will now become a valued team member to help us further empower our members to reach their health and weight goals.

By Anne Mullens

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@william26991407 Rob Hanna
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@MarkMyerson Richard Beall

Protein Composition and Structure

Secondary structure refers to the shape of a folding protein due exclusively to hydrogen bonding between its backbone amide and carbonyl groups. Secondary structure does not include bonding between the R-groups of amino acids, hydrophobic interactions, or other interactions associated with tertiary structure.

The two most commonly encountered secondary structures of a polypeptide chain are alpha-helices and beta-pleated sheets. These structures are the first major steps in the folding of a polypeptide chain, and they establish important topological motifs that dictate subsequent tertiary structure and the ultimate function of the protein.

Ramachandran plot


An alpha-helix is a right-handed coil of amino-acid residues on a polypeptide chain, typically ranging between 4 and 40 residues. This coil is held together by hydrogen bonds between the oxygen of C=O on top coil and the hydrogen of N-H on the bottom coil. Such a hydrogen bond is formed exactly every 4 amino acid residues, and every complete turn of the helix is only 3.6 amino acid residues. This regular pattern gives the alpha-helix very definite features with regards to the thickness of the coil and the length of each complete turn along the helix axis.

The structural integrity of an alpha-helix is in part dependent on correct steric configuration. Amino acids whose R-groups are too large (tryptophan, tyrosine) or too small (glycine) destabilize alpha-helices. Proline also destabilizes alpha-helices because of its irregular geometry its R-group bonds back to the nitrogen of the amide group, which causes steric hindrance. In addition, the lack of a hydrogen on Proline's nitrogen prevents it from participating in hydrogen bonding.

Another factor affecting alpha-helix stability is the total dipole moment of the entire helix due to individual dipoles of the C=O groups involved in hydrogen bonding. Stable alpha-helices typically end with a charged amino acid to neutralize the dipole moment.


  • 3.6 amino acids per turn
  • 0.54 nm per turn
  • side chains pointed out
  • H-bonds parallel to axis
  • n-4 H-bonds
  • dipole moment (neg. at C end)
  • no pro, less gly, ser
  • limited similar side chain charges


This structure occurs when two (or more, e.g. psi-loop) segments of a polypeptide chain overlap one another and form a row of hydrogen bonds with each other. This can happen in a parallel arrangement:

Or in anti-parallel arrangement:

Parallel and anti-parallel arrangement is the direct consequence of the directionality of the polypeptide chain. In anti-parallel arrangement, the C-terminus end of one segment is on the same side as the N-terminus end of the other segment. In parallel arrangement, the C-terminus end and the N-terminus end are on the same sides for both segments. The "pleat" occurs because of the alternating planes of the peptide bonds between amino acids the aligned amino and carbonyl group of each opposite segment alternate their orientation from facing towards each other to facing opposite directions.

The parallel arrangement is less stable because the geometry of the individual amino acid molecules forces the hydrogen bonds to occur at an angle, making them longer and thus weaker. Contrarily, in the anti-parallel arrangement the hydrogen bonds are aligned directly opposite each other, making for stronger and more stable bonds.

Commonly, an anti-parallel beta-pleated sheet forms when a polypeptide chain sharply reverses direction. This can occur in the presence of two consecutive proline residues, which create an angled kink in the polypeptide chain and bend it back upon itself. This is not necessary for distant segments of a polypeptide chain to form beta-pleated sheets, but for proximal segments it is a definite requirement. For short distances, the two segments of a beta-pleated sheet are separated by 4+2n amino acid residues, with 4 being the minimum number of residues.


A similar structure to the beta-pleated sheet is the alpha-pleated sheet. This structure is energetically less favorable than the beta-pleated sheet, and is fairly uncommon in proteins. An alpha-pleated sheet is characterized by the alignment of its carbonyl and amino groups the carbonyl groups are all aligned in one direction, while all the N-H groups are aligned in the opposite direction. The polarization of the amino and carbonyl groups results in a net dipole moment on the alpha-pleated sheet. The carbonyl side acquires a net negative charge, and the amino side acquires a net positive charge.

How Do High-Protein Diets Affect You?

Some weight-loss programs, like the Atkins Diet and the Ketogenic Diet, call for high amounts of protein and fat while limiting carbs. But research shows that they seem to primarily work well only in the short-term. One reason may be that people aren’t able to stick with this type of eating plan over a long period of time.

Be mindful of what diets you try. Focusing just on protein and fat can keep you from getting all the nutrients you need, and that can lead to unhealthy side effects. That can lead to fatigue, dizziness, headaches, bad breath and constipation.


Leah Thomas, RD/LD, CSSD, Assistant Athletics Director for Student-Athlete Development, Georgia Tech Athletic Association, Atlanta.