On the subject in the title: Protein density versus volume when you cannot eat much Working notes rather than a conclusion.
Something about protein density versus volume does not reconcile and I would like a second pair of eyes before I decide which half is wrong.
Two sources, both reputable, giving figures that cannot both be right unless they are measuring different quantities. My suspicion is that they are, and I cannot see how.
On the opening post — agreed on the reasoning, with one qualification.
Timing of protein: spreading protein intake across the day, with some at each meal, is more practical than trying to hit the whole target at one sitting on suppressed appetite.
Eating anything at all: on substantial appetite suppression, eating enough total calories to maintain lean mass is the priority. Protein comes second to total intake.
I am aware this is the third time this month I have made this point.
The useful distinction on protein density versus volume is between what was measured and what was inferred from it. Both end up in the same sentence and only one of them has error bars.
Fibre and fluid tend to fall alongside protein when intake drops, and the constipation reported here follows from that as much as from the mechanism.
Happy to be the one who is wrong here if it settles the question.
Protein targets during weight loss: the standard recommendation is 1.6 to 2.2 grams per kilogram of body weight. Individual requirements vary but that range is a reasonable starting point.
Noting that I have skin in this question and have tried to discount for it.
Practical note on protein density versus volume: write down what you expect before you look. The number of times I have found what I went looking for is higher than chance would allow.
Taking post #11 at face value and following it one step further.
Renal considerations around higher protein intake apply to people with existing renal impairment and are frequently generalised beyond that population.
That is my reading. Someone else read the same page differently and was reasonable.
I read post #11 twice before replying, because I had assumed the opposite.
What tends to work is front-loading the day, prioritising density over volume, and treating it as a solvable problem rather than an inconvenience.
Published guidance on protein during weight loss is reasonably consistent and is easy to find, which makes this one of the better-evidenced practical questions here.
Where intake has fallen a long way, protein is usually the first thing to fall because it is the least appealing macronutrient when appetite is reduced.
That is all the detail I have. Someone else will have more.
Reading back through the protein density versus volume threads from last year, the same three questions come up every time and only one of them has ever been answered properly. That seems like a documentation gap rather than a knowledge gap.
Everything in post #15 holds. The case it does not cover is the one I have.
Micronutrient adequacy becomes a real question at very low total intake and is much less discussed than protein.
I would want a second opinion before relying on that.
Nothing to add on the substance. Thank you for taking the question at face value.
On post #15 — agreed on the reasoning, with one qualification.
Meeting protein targets on suppressed appetite: this is where the practical difficulty lies. Eating more protein when appetite is suppressed is genuinely hard. Front-loading the day, prioritising density over volume, and accepting this is a problem worth solving all help.
Adequate protein during a substantial deficit is the part of this conversation that gets least attention and probably deserves most.
Protein sources: animal sources (meat, fish, eggs, dairy) are denser and easier to hit targets with. Plant sources require higher volume. Neither is nutritionally superior; volume and personal preference matter.
Caveat: everything above assumes the paperwork is what it says it is.
Noted, and I have changed what I was going to do on the strength of it.
Post #20 is the version of this I will quote in future. One addition.
Leucine and MPS: leucine stimulates muscle protein synthesis at a threshold of roughly 2 to 3 grams per meal. That influences how much protein per meal matters, but total daily protein still matters most.
Protein density versus volume is worth one more sentence than it usually gets, and the sentence is the one about how the number was arrived at.
Answering the question post #23 raises rather than the one it answers.
Protein supplements: whey, casein, and plant-based protein powders can help hit targets when whole-food intake is limited by appetite. Protein quality (all essential amino acids) matters more than form.
Flagging that the sources on this are thinner than the confidence in the thread suggests.
Micronutrition alongside protein: eating protein foods that are also good sources of micronutrients (iron, B vitamins, zinc) solves two problems at once.
Protein supplements: whey, casein, and plant-based protein powders can help hit targets when whole-food intake is limited by appetite. Protein quality (all essential amino acids) matters more than form.
The part I am sure of is shorter than the part I have written.
Narrowing post #28, because the general version has more than one answer.
The mechanism is not mysterious. Substantial energy restriction with inadequate protein and no resistance stimulus loses lean tissue as well as fat.
That much is documented. The rest is how I have interpreted it.
Everything in post #26 holds. The case it does not cover is the one I have.
The most useful thing anyone has posted about protein density versus volume in this category was a table of what had been measured and by whom. That is what I would want again.