8 July 2020
Nutrition and health Pt.1: A review of macronutrient targets
How much protein should I eat? What about carbs? Fats? What types? What about vitamins and minerals? Questions such as these are asked of nutritionists, dieticians and even PT’s and doctors. And rightfully so, too. High-quality/fully thought-out answers, however, often aren’t always at the disposal of these professionals, due to a small glitch in the…
How much protein should I eat? What about carbs? Fats? What types? What about vitamins and minerals?
Questions such as these are asked of nutritionists, dieticians and even PT’s and doctors. And rightfully so, too.
High-quality/fully thought-out answers, however, often aren’t always at the disposal of these professionals, due to a small glitch in the education system. The guidelines that are used to educate the public also tend not to be up to scratch.
In the short term, this often misconstrued information is, typically, inconsequential. It usually does result in some health and fitness progress (if adhered to), but as typically the case, the sad fact is, better results were there for the taking all along.
The crux of this article, however, is to review healthy eating targets and justifications, cross-comparing them with the Australian guidelines. I am looking at the longer-term effects—not the shorter-term, inconsequential ones—of the most readily available information for how Australian’s are suggested to eat.
From the outset, I will say that the guidelines are mostly well-constructed, but a few areas could do with some slight adjustments and a more well-rounded discussion surrounding them.
I’ll be taking apart a few of the studies used by the creators of the guidelines due to the quality, or lack thereof, and the somewhat short-sighted conclusions that followed. Most of this will pertain to the targets set for protein.
This issue with short-term research for nutrient targets is that is doesn’t fully comprehend the long-term implications.
To be fair, though, no research will be able to fully acknowledge the health gained or lost by small upgrades that are constantly implemented over a large expanse of time. Not without a mountain of confounding variables at least. Some studies though, especially when the long-term consequences are considered, are most definitely better than others at bridging this gap.
For example, if X recommendation is allowing you to be healthy (by research definitions) now, it may not be conducive to the same level of health in the future. Instead, if you substituted Y from the beginning, all the potential health that could be gained would remain across time, granted there are no special circumstances.
Hopefully, as I present a comprehensive and holistic view on each macronutrient, what I’m trying to say will become clearer.
What I’m not seeking or pushing, however, is the optimisation of health.
I am just going to try and present the best information I can on healthy eating, and the role of macronutrients within that process. Whatever you do with that information is up to you. This is a guide. The practical part can come later…
I will say this, because the optimisation, in reality, is a fallacy.
We are simply too dynamic, biased, emotional and, ultimately, human to even pursue optimisation with any success. But despite perfection’s unreachable status, that doesn’t mean that you shouldn’t aim in that general direction.
I hope you do take some of this information and make healthier choices that cooperate with the idiosyncrasies of your life.
I’m bringing the Australian guidelines into the spotlight for three reasons.
- These guidelines are what inform tertiary nutrition experts, therefore, it’s the most commonly prescribed advice.
- As previously stated, there are a few key areas that need updating/a more nuanced outlook.
- Because of reasons 1 & 2, you’ll need evidence to back up claims against the norm. Which I am planning to arm you with.
The Australian Guidelines (not necessarily the nutrient reference value website) only get updated approximately every 10 years. This rate of turnover may have been acceptable 20-30 years ago, but with the rapidly expanding field of nutrition science, this rate of updating leaves a deficit for all those who draw from it.
The guidelines are due to change in a few years, but I don’t expect much to come of it. From my understanding, it will mostly be results and follow up studies from the National nutrition & physical activity survey from 2013 (a lot of which has been added to the website) as well as a greater focus towards sustainable diets for the environment.
For the most part, the Australia Guidelines and Guide To Healthy Eating (being a summary of the guidelines with more practical advice) are very useful, and I have absolutely no doubt that if everyone followed our countries guidelines to the letter, obesity would be scarce, and the health care system and the economy would be relieved of significant pressure.
I’m really only going to nit-pick on a few advised targets and some of the more general advice. Because sometimes you deserve better, right?
Before Macronutrient targets can even enter your sphere of thought, though, we must first look at energy balance.
Over time, the balance of calories (energy IN vs energy Out) will have the greatest impact on your health in regard to dietary influences—provided you aren’t prone to drinking bleach.
Calories provide the energy needed to support life, for better or for worse. The list of health consequences for both under and overnutrition is longer than I care to list, but to summarise (mostly because it’s beside the point of this article), they both increase the risk of all-cause mortality (in the long run) and impede on all facets of health.
Weirdly enough, we live in a time when both the overconsumption of calories as well as malnourishment, is simultaneously leading to overweight but undernourished individuals. As you can imagine, this is not a healthy combination.
In Australia, approximately two-thirds of adults are either overweight or obese (1)and according to Australia’s most recent nutritional survey (2012-13), almost half of our diet (42%) comes from ultra-processed food (2). The stats on fruit and veg intake are also pretty grim.
Elderly people, on the other hand, have a higher prevalence of undernutrition which is defined by the loss of muscle, fat and/or bone mass (11-44%) (3). One key, as mentioned in the cited article, is to get on top of it early and in particular; strive to maintain or grow muscle mass.
When discussing healthy eating, it’s crucial to first consider caloric intake, and to have the opportunity to do so is a gift we can’t take for granted.
Unfortunately, it would be inappropriate to generalise caloric intakes. Not all females need 1600kcal p/d and not all males required 2500 kcal; One thing I’ve learned from coaching, is that it varies wildly.
Individual calculations based on ever-changing life circumstances are what’s required.
Some of you will require guidance for determining calories to get yourself to a weight that is conducive to current and long-term health. This, however, doesn’t change the recommendations below, only the framework and priorities within that caloric framework.
One thing is for sure, though, if you do follow these recommendations, you’ll have a wayyyy easier time getting into a calorie-appropriate dietary intake.
Nutrition Reference Values
Recommended Daily Intake (RDI for short) is most likely a term you’ve come across before and it’s something I want to briefly touch on, because it is the unit of measurement that I will refer to throughout this article and the sequel (coming soon) regarding micronutrients.
Estimated Average Requirements(EAR) – Requirements of a nutrient to support the healthy function of approx. 50% of the population.
Recommended Daily Intake (RDI)– Requirements of a nutrient to support the healthy function of approx. 98% of the population. This is a calculation based off of EAR.
Essentially researchers will have large cohorts of people, figure out the estimated average intakes requirements and then add 2 standard deviations to produce RDI.
Adequate intake (AI) – used when in place of RDI when there is not enough evidence.
Upper limit (UL) – The highest possible daily nutrient intake to pose no adverse health effects.
Protein, fats and carbohydrates
The Australian guide to healthy eating has set RDI’s for Protein, an AI for fats and nothing set for carbohydrates.
Alongside RDI’s is the Acceptable Macronutrient Distribution Range (AMDR)
A few things I have to say about this distribution…
- Percentages are risky for individuals who maintain weight on low calories because 15 or 20% of sweet f-all calories, is again, sweet f-all. This may lead to deficiencies, which you’ll read about in the section on fats, but it applies to protein, too.
- It creates the illusion that stepping over the boundaries is unhealthy, yet I can think of at least a few reasons why this would not actually be the case.
19-50yr 64g/day (0.85g/kg)
>70yr 81g/day (1.07g/kg)
19-30yr 46 g/day (0.75g/kg)
>70yr 57g/day (0.94g/kg)
These are the current Australian government recommendations for protein.
According to the research used, the above amounts of protein is needed for the maintenance of fat-free mass and health (4). The target, as you can see, rises at the age of 70 for both genders to combat age-related muscle degeneration (5).
The RDI’s represent a 12% deviation from the EAR studies on protein which was a meta-analysis of 19 studies with 235 healthy adults, only 14 of which were elderly. At least 3 protein feedings had to be observed whilst measuring nitrogen balance (nitrogen being an element exclusive to protein).
At the present time, measuring nitrogen balance is an out of date technique, and the conclusions based on 3 feedings were, quite simply, never in date…
What this more accurately represents is the minimum amount needed to avoid deficiency. Avoiding deficiency is one thing, being proactive and prosperous in the future is another.
0.8g/kg may be enough for a large percentage of the population to maintain muscle in the short-term but for 98% of the population, from youth to old age, it begs the question. A question that can never be answered by 3 feedings.
For starters, protein has many functions within the body, including growth and repair of tissues, such as hair, muscle and the developing brain. It also helps maintains healthy immune function, among other things. Make no mistake, this is a shortened version of the complete list.
Secondary and indirect functions for health are also seen in protein’s satiating properties.
Chronic deficits in protein (or total energy for that matter) will render these beneficial functions as progressively more trivial.
A bit more about protein
Protein has two forms…
Complete proteins– All 9 essential amino acids are available as well as non-essential. Found in meat, poultry, seafood and dairy.
Incomplete protein – Missing at least 1 essential amino acid. Found in plant-based proteins.
These distinctions are important to have in mind because not every function can be filled by incomplete sources, such as muscle growth.
Current research, using the Indicator Amino Acid Oxidation method (IAAO), which is a superior way of measuring protein needs for populations, has helped develop a better understanding of requirements (6). Through the use of this technology, it has been determined that to fulfil proteins many functions and protect against age-related sarcopenia, 1.2-1.6g/kg/d of protein is what’s required (7).
To say that sarcopenia presents itself at age 70, or at least that combating it should start then, is also misleading and extremely consequential—not in a good way.
For those of you that don’t know, sarcopenia is a progressive loss of skeletal muscle due to anabolic resistance, meaning you just don’t get the same stimulus and results out of exercising (or the same amount of protein ingested) as you get older. In healthy ageing, however, muscle protein synthesis (MPS) and breakdown (MPB) doesn’t actually significantly change.
This process becomes significant in your 30’s—which is why natural bodybuilders struggle past those years—and really kicks into second gear around the age of 60 (8).
Therefore, eating 1.2g+/kg from your inception into adulthood will give you a greater chance at having autonomy and avoiding fall-risks in your older years. More muscle equals more bone mineral density and a greater ability to move, allowing the retention of even more muscle. It’s the Matthew Principle of muscle and movement.
Per meal recommendations are also just as important to the elderly (60+), as total daily intake is, for saving muscle. This has been demonstrated when comparing several small protein feedings to a large single feeding that reaches the leucine threshold (9). Essentially, one larger feeding has better muscle sparing properties.
2.5g of leucine is the official threshold but it may be slightly higher for the elderly (10).
Two things are important to note when discussing leucine thresholds…
- Leucine triggers Muscle Protein Synthesis (MPS) but to build muscle, you still require all of the other essential and non-essential amino acids.
- Complete protein sources i.e. animal bases protein are the sources of protein that are rich in leucine. Vegetables won’t cut it.
In a highly concentrated complete protein such as whey powder, you’ll only need 0.3g/kg per meal or around 20-25g of protein, but in mixed meals, still with complete sources such as meat, it’s likely closer to 0.5g/kg per meal. That typically equates to about 30g of protein per meal.
Timing also matters.
After MPS has peaked, the muscles become unresponsive (known as a ‘refractory period’) to any more incoming amino acids for approximately 4 hours, if given a highly concentrated dose (11). A regular mixed meal with fats and carbs, however, may take longer to initiate this refractory period. When breaking down the standard 16-hour day, the refractory period leaves 3-4 windows of opportunity to peak MPS and therefore grow or retain muscle.
Lastly, and importantly, given the statistic regarding obesity, protein’s satiating effects are a much-needed discussion point with regards to health.
When measuring ghrelin (hunger hormone) after a calorie-controlled high or low protein meal, high protein resulted in decreased plasma ghrelin (12), and this is also true of a 24-hour high protein diet (13). There’s even some evidence of spontaneous calorie reductions ( 441 +/- 63 kcal/day) and subsequently significant weight loss following an ad libitum diet containing 30% protein compared to 15% (14).
There are, of course, exceptions to the rule; if the most satiating carbohydrate or fat sources possible were compared to proteins lowest within a calories-controlled meal, I doubt the same outcomes would prevail.
The satiating effects of protein may even extend beyond 1.6g, making a case for even higher protein intakes.
Exactly how far? I don’t know, and it will depend on your dieting circumstances. What I do know is that most of you will have more room in your diets for protein without invading on dietary fat and carbohydrate requirements (as you’ll soon find out).
Another 0.1-0.9 is likely still within practical limits for the majority of you. The only caveat is for those who have limited calories to play with such as people who maintain weight on <1200 kcal per day.
Protein targets per day: 1.2-1.6kcal/kg/d
Per meal: 0.3g for whey protein and likely to be 0.5g/kg for mixed meals equating to 3-4 protein window per day. For ages 60yr+, at least get one bolus dose.
Protein sources: To give yourself the best chance of staying within your caloric goldilocks zone or to lose weight, lean poultry, meats, seafood and dairy protein, mixed in with plant-based sources are your go-to.
It’s hard for researchers to quantify how many grams of fat an individual will need per day. Instead, they focus on the requirements of individual essential fatty acids.
There are four categories for dietary fats
Monounsaturated (Oleic acid)
Found in Olive oil, avocado and most nuts.
Saturated (Lauric acid, stearic acid & Palmitic acid)
Found in meat, dairy, butter, palm oil and coconut oil.
Trans fat (Elaidic acid)
Found in fried food, pastries, and ultra-processed foods.
Polyunsaturated (linolenic acid & adrenic acid)
Found in safflower oil, salmon and walnuts.
Whilst there are many fatty acids, only three are 3 essentials.
Essential always means that they can’t be produced (sufficiently) endogenously, therefore we require acquiring them through our diet.
Alpha-Linolenic acid (Omega 3 Polyunsaturated fatty acid)
Found in nuts, linseed and canola oils and margarines.
Linoleic acid (Omega 6 Polyunsaturated fatty acid)
Found in seed oils (sunflower, safflower and corn)
EPA & DHA (Omega 3 Polyunsaturated fatty acid)
Found in oily fish such as herring, salmon, sardines and tuna
Note: Not technically essential, but for health, I dare say it is the most important—sparing deficiencies.
Essential and non-essential dietary fats go on to produce of our sex-hormones which help regulate mood, libido and muscle growth/retention. Vitamins A, D, E and K also require the presence of dietary fats to be absorbed after digestion has occurred. Deficiencies in these vitamins are not pleasant, nor are they necessarily easy to detect. Fat is also another key player in maintaining healthy immune function and, of course, has satiating properties of its own.
Currently, for fat, no g/kg amount is prescribed due to limited research. Instead, the fatty acid prescriptions are based on the median intakes of healthy adults conducted in a 1995 survey. From that, an Adequate Intake was determined.
The Australian Guide to Healthy Eating suggests eating 20-35% of your total calories from fat. This is reasonable in the majority of cases but If you’re eating 1400 calories (which is a common eucaloric scenario for females), weighing 67kgs, the result is…
Roughly 0.4-0.8g/kg bw
Hopefully this demonstrates the problem with percentage-based advice, and this same problem can play out with protein.
On a chronic basis, 0.4g could be too low.
The Australian Guide to Healthy Eating pushes a low-fat diet with little (quality) reasoning, and really, the percentages used have no scientific basis—besides the fact that you do need some dietary fats.
From what I can gather it’s due to the energy content of fats being higher than carbohydrates and protein, as well as the perceived CVD risk that causes this.
To be fair, there is some merit to both concerns. Fats are more energy-rich but that doesn’t always equate to, or account for all overconsumption, and there are CVD risks to some fatty-acids, but certainly not all.
Saturated fats cop the bulk of the scrutiny (for CVD risk) with very little emphasis on trans fats (aka hydrogenated oils). If you go through the full manuscript, it’s almost as if the people writing about it forgot about trans fats, remembered it last minute, and threw it in here and there with saturated fats to cover their behinds.
The net result is a guide to limit saturated fat to <10% of dietary intake and that total fat shouldn’t go over 35% of total caloric intake.
Whilst I mostly agree with this, I believe limiting saturated fats to sub 10% and talking about them the way that is typically done, can lead to some (or many) misconceptions and demonise all foods containing saturated fats. Some caveats are needed.
Fats in greater detail….
As you can hopefully see from above, Polyunsaturated fats are the only essential fatty acid, but as is the theme of this discussion, essentialist thinking doesn’t necessarily win you the best health.
On the other hand, Monounsaturated fats (MUFAs for short) are also deemed as one of the “good” fats, and for good reason.
A comprehensive systematic review of cohort studies found a significant reduction in CVD with diets high in MUFAs, more specifically olive oil (oleic acid), but also acknowledged a lack of research with regards to other MUFA-sources (15).
What’s more fascinating to me, is the real-world examples of diets high in MUFAs from more than one source, as well as a few other non-MUFA fatty acids.
The Mediterranean diet—with its fat content predominantly coming from nuts, olive oil, avocado, legumes and leafy vegetables and fish—given to people with cardiovascular risk, significantly reduced the chance of any event (16).
Of course, there is still a high percentage of poly-unsaturated fats, but MUFAs dominate and there’s little saturated fat. Other variables for CVD risk reduction were at play as well, but the point is; monounsaturated fats are certainly not something to leave out on the basis on essential-recommendations, and they can’t be grouped into a CVD risk profile.
Now let’s decipher between saturated and trans fats
“Trans-fat act like saturated fats in the body” – The Australian Guide to Healthy Eating
The first reason for this stomach-churning statement is that, for reasons unknown to me, early research lumped saturated fats in with trans fats. Results, obviously, were not good. An increased risk of every subcategory of cardiovascular disease was notable.
Thankfully, a systematic review and meta-analysis split them up and the difference was night and day. Trans fats were the perpetrator and saturated fats were the wrongly convicted (17).
The investigations didn’t stop there, and rightfully so, there was still a lot to learn about this newly exonerated fatty acid. But once again, follow up studies, and their cruel designs, demonised saturated fats.
The designs were unfair because they used one saturated fat source, in abundance, across significant amounts of time. A commonly cited study of 7-week interventions, using muffins made with palm oil (SFA’s) versus sunflower oil (PUFAs) results in higher accumulations of visceral (central) fat tissue. Palm oil is made of palmitic acid, and it is the one saturated fatty acid that seems to wreak the most havoc on blood lipids and health.
When consumed in a more normalised manner, with saturated fatty acids from milk and cheese, or coconut oil, or a mix of both, the same results just don’t play out.
A meta-analysis of twenty-one epidemiological studies showed no association between diets containing saturated fats and CVD (18). Even including butter in your diet seems to have no significant impact on your health (19), not that it’s necessarily adding to your health, either.
I do acknowledge the beneficial effects of replacing saturated fats with polyunsaturated fats that are shown in the research (20), but I consider the results to be mostly unimpressive and the individual studies to be unlike a normal diet containing saturated fats.
There are, to be fair, some people with certain genes that are saturated fat sensitive, making them more likely to see negative impacts of blood lipids. These people should be wary, but it is by no means a cause for widespread concern.
Saturated fats aren’t so bad, and as you’ll now know, it depends on where you get them from, as well as for how long and what else you’re eating them with.
At this point, that 10% barrier looks very shaky when breached by predominately dairy fats, who’s health returns are overwhelmingly positive. However, the truth is unsaturated fats, especially omega 3’s and MUFAs are just way better, which makes a conceptual boundary close to 10% valid—just not for the same reasoning.
The point is, a diet biased towards one fatty acid source is bound to cause problems and variety in fats is, therefore, the key. Even polyunsaturated acids aren’t free from this rule.
Omega-6 and omega-3 polyunsaturated fatty acids are left and are both essential as you’ll recall.
So just predominately eat them, right?
For greater heart health, there’s some evidence to suggest that the ratio between omega-3 and omega-6 is worth nothing.
Because the average western diet contains a lot of red meat, eggs, nuts, avocado and seeds as well as vegetable oils—that are high in omega 6—whilst simultaneously lacking in oily fish (omega 3), the average ratio is 15:1 -17:1 (21).
Whilst some research is showing that ratios between 1:1 – 5:1 lends itself to greater health markers, what’s more likely, is that the low omega-3 content of diets is the main issue at hand, and when that’s resolved, omega-6 intake is less concerning (22).
More research is required, but one thing is for sure, omega-3’s, specifically from EPA and DHA are the alpha and omega of fatty acids.
Omega-3’s benefits for cardiovascular health are well known but they also might help protect against neurodegenerative diseases, anabolic resistance in the elderly, depression and maybe even very, very, very lightly facilitate weight loss through some super indirect means.
So, how much do you need?
Well, that depends on the aim, but at least 500mg/day of mixed EPA & DHA for healthy individuals and around 800-1000mg/day for individuals with known cardiovascular problems (23), but be sure to speak to your doctor first, especially if you’re on blood thinners.
If you don’t eat oily fish regularly then supplementation might be wise.
- I can’t give you a grams/kg guide based on research. However, from experience with myself, clients, co-workers and nutritional experts, I can say that healthy (long term) seems to come at a minimum of 0.5g/kg – 0.8g/kg and the max depends on protein and carbohydrate needs as well as where you get your fats from.
- 20% may be too low in some cases
- Saturated fats aren’t bad, especially if it’s from dairy sources, unsaturated is just better.
- Aim to get a variety of fats, mostly from unsaturated omega-3 sources and considering fish oil supplementation of you struggle to eat oily fish.
- Total fat beyond 35% can be healthy and it doesn’t necessarily pose a threat to total caloric limits overtime.
You may have heard that Glucose (broken down carbohydrate) is the Central Nervous Systems’ preferred source of fuel, and this is undoubtedly true. In fact, it is essential for the brain—but not essential in our diet, because we can produce these molecules from non-carbohydrates sources through a process called gluconeogenesis, leaving us with no EAR, RDI or AI.
However, non-essential does not necessarily equal to non-beneficial.
Carbohydrates have several benefits to health including…
- Fibre, which comes predominately from carbohydrates sources such as fruit, veg and whole grains, aiding predominately in bowel health as well as other areas.
- Fibrous food that is of equal importance for satiety as protein.
- Insulin, a hormone that is secreted (mostly) after carbohydrate intake and is a powerful anticatabolic hormone which helps spare protein within the body. It is also a satiety signalling hormone.
- Fruit, veg and wholegrains carry vital micronutrients and phytochemicals
The harder question is: How can we figure out a range that is conducive to health?
Looking at fruit, vegetables, whole grains and total fibre will suggest a minimum answer.
How much do we need and what it does for our health?
A recent systematic review and metanalysis of just below 135 person-years from 185 prospective (observational) studies and 58 clinical trials which involved 4635 adult participants concluded the following….
“Suggested as 15-30% decrease in all-cause mortality and cardiovascular-related mortality, and incidence of CHD, stroke incidence, T2 diabetes, and colorectal cancer when comparing the highest dietary fibre consumers with the lowest consumers”
“The clinical trials show significantly lower body weight, systolic blood pressure, and total cholesterol” (24)
The greatest risk reduction was seen in intakes between 25-29g which fits in line with the common advice to eating around 30g/day and the advice given in the Australian guidelines.
Mum was right, eat your damn veggies.
Well, veggies, fruit and whole grains mostly. Plant-based foods, such as nuts and beans, also have high fibre profiles.
As long as it’s not all coming from protein bars and other artificially fibrous products—as I have no doubt that a solid portion of the health benefits associated with fibre came from the wholesome food themselves and their nutrient-dense profiles.
This leads me to my next point…
I believe, well, I hope it’s common knowledge that fruit and vegetables are extremely important for health, not just due to fibre content but for the micronutrition they carry.
The vitamins, minerals and phytochemicals they contain also play a role in the protection of health, not only the fibre.
In epidemiological research, you can discover a significant protective effect of fruit and vegetables and basically all cancer types you can possibly think of. A now-famous epidemiological review, examining over 200 studies revealed a nearly twice as high risk of cancer when consuming low fruit and veg intake compared to high (25).
When comparing other observational reviews, that number dropped as low as 11% and as high as 40% for cancer risk resulting from inadequate fruit and veg intake. With thousands of confounding variables at play, it’s impossible to know. What the enormous amount of research does suggest is that there is a significant risk of not eating fruit and veg.
In one review, reductions in all-cause mortality seemed to hit a threshold when consuming 5 servings of fruit and vegetables per day (26), in other, it was estimated at 600-800g grams of combined fruit and veg (27). A more specific study showed that >5 servings of fruit and veg resulted in a 26% reduction in stroke (28).
What may not be common knowledge is that whole grains carry high amounts of phytochemicals (think of them as antioxidants) and other micronutrients that have similar, if not the same, protective effects (29).
5 servings of veggies are in line with the Australian Guide to Healthy Eating for Adults with a serving size equalling 75g, or ½ cup of veggies, and it’s around 2 servings for fruit. 6 servings of whole grains are recommended for most adults and a serving is 120kcal. That’s 720kcals from grains. I really don’t think that much is needed, nor do I think its inherently too much.
Vitamins and mineral are not exclusive or necessarily predominant to carbohydrates, though. Red meat, for example, is high in Iron and B12, which are harder to come by in other foods. Calcium is harder to come by if you don’t consume dairy. Phytochemicals, on the other hand, are exclusive to plant-based sources which are mostly carbohydrate orientated, and these chemicals have to account for some of the benefits listed above.
To get 30g of fibre, 5+ servings of fruit and veg and some whole grains, I dare say you’ll need at minimum 1g/kg of carbs in your diet.
The better way to go about this is to set protein and fats first, then fill the rest of your calories with carbs. Just keep in mind, that if you ever go the low-carb route for dieting, don’t drop below 1g/kg—and have that be almost exclusively fruit, veg and whole grains.
- 5+ servings of fruit and veggies, as well as some whole grains, should be your predominant carbohydrate source
- 25-30g of fibre is ideal
- It’s likely that you’ll need at least 1g/kg/d carbohydrates to get enough of the good stuff
- The easier way to think about it is to fill the remaining calories with carbohydrates
Granted you haven’t filled up your caloric limits with everything listed above (which is always priority number one), the rest I leave up to you. As long as it’s not trans fats—well, at least not frequently or in high doses—then there’s no problem with having some discretionary foods. There’s no evidence to suggest added sugars will do harm if calories are kept within your “Goldilocks zone” and if the vast majority of your diet is wholesome and varied.
Micronutrition is next up which will include common deficiencies and misconceptions such as salt being unhealthy as well as a food list that will complement this article, especially if you’re lost for healthy food options.
1. National Health Survey: first results, Australia 2017-18. [Canberra, A.C.T.]: Australian Bureau of Statistics; 2018.
2. Machado PP, Steele EM, Levy RB, Sui Z, Rangan A, Woods J, et al. Ultra-processed foods and recommended intake levels of nutrients linked to non-communicable diseases in Australia: evidence from a nationally representative cross-sectional study. BMJ Open. 2019;9(8):e029544.
3. Flanagan D, Fisher T, Murray M, Visvanathan R, Charlton K, Thesing C, et al. Managing undernutrition in the elderly Prevention is better than cure. Australian Family Physician. 2012;41:695-9.
4. Rand WM, Pellett PL, Young VR. Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults. The American journal of clinical nutrition. 2003;77(1):109-27.
5. Campbell WW, Evans WJ. Protein requirements of elderly people. European Journal of Clinical Nutrition. 1996(SUPP1):180.
6. Pencharz PB, Elango R, Wolfe RR. Recent developments in understanding protein needs – How much and what kind should we eat? Appl Physiol Nutr Metab. 2016;41(5):577-80.
7. Phillips SM, Chevalier S, Leidy HJ. Protein ‘requirements’ beyond the RDA: implications for optimizing health. Applied Physiology, Nutrition, and Metabolism. 2016(5):565.
8. Janssen I, Heymsfield SB, Ross R. Low relative skeletal muscle mass (sarcopenia) in older persons is associated with functional impairment and physical disability. 2002. p. 889-96.
9. Arnal MA, Mosoni L, Boirie Y, Houlier ML, Morin L, Verdier E, et al. Protein pulse feeding improves protein retention in elderly women. Am J Clin Nutr. 1999;69(6):1202-8.
10. Katsanos CS, Kobayashi H, Sheffield-Moore M, Aarsland A, Wolfe RR. A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly. Am J Physiol Endocrinol Metab. 2006;291(2):E381-7.
11. Atherton PJ, Smith K. Muscle protein synthesis in response to nutrition and exercise. J Physiol. 2012;590(5):1049-57.
12. Blom WA, Lluch A, Stafleu A, Vinoy S, Holst JJ, Schaafsma G, et al. Effect of a high-protein breakfast on the postprandial ghrelin response. Am J Clin Nutr. 2006;83(2):211-20.
13. Lejeune MP, Westerterp KR, Adam TC, Luscombe-Marsh ND, Westerterp-Plantenga MS. Ghrelin and glucagon-like peptide 1 concentrations, 24-h satiety, and energy and substrate metabolism during a high-protein diet and measured in a respiration chamber. Am J Clin Nutr. 2006;83(1):89-94.
14. Weigle DS, Breen PA, Matthys CC, Callahan HS, Meeuws KE, Burden VR, et al. A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Am J Clin Nutr. 2005;82(1):41-8.
15. Schwingshackl L, Hoffmann G. Monounsaturated fatty acids, olive oil and health status: a systematic review and meta-analysis of cohort studies. Lipids Health Dis. 2014;13:154.
16. Estruch R, Ros E, Salas-Salvadó J, Covas MI, Corella D, Arós F, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013;368(14):1279-90.
17. de Souza Russell J, Mente A, Maroleanu A, Cozma Adrian I, Ha V, Kishibe T, et al. Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes : systematic review and meta-analysis of observational studies. BMJ: British Medical Journal. 2015;351.
18. Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr. 2010;91(3):535-46.
19. Pimpin L, Wu JH, Haskelberg H, Del Gobbo L, Mozaffarian D. Is Butter Back? A Systematic Review and Meta-Analysis of Butter Consumption and Risk of Cardiovascular Disease, Diabetes, and Total Mortality. PLoS One. 2016;11(6):e0158118.
20. Mozaffarian D, Micha R, Wallace S. Effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat: a systematic review and meta-analysis of randomized controlled trials. PLoS medicine. 2010;7(3):e1000252-e.
21. Simopoulos AP. Evolutionary aspects of diet, the omega-6/omega-3 ratio and genetic variation: nutritional implications for chronic diseases. Biomed Pharmacother. 2006;60(9):502-7.
22. Mozaffarian D, Ascherio A, Hu FB, Stampfer MJ, Willett WC, Siscovick DS, et al. Interplay between different polyunsaturated fatty acids and risk of coronary heart disease in men. Circulation. 2005;111(2):157-64.
23. Lavie CJ, Milani RV, Mehra MR, Ventura HO. Omega-3 polyunsaturated fatty acids and cardiovascular diseases. J Am Coll Cardiol. 2009;54(7):585-94.
24. Reynolds A, Mann J, Cummings J, Winter N, Mete E, Te Morenga L. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet. 2019;393(10170):434-45.
25. Block G, Patterson B, Subar A. Fruit, vegetables, and cancer prevention: A review of the epidemiological evidence. Nutrition and Cancer. 1992;18(1):1.
26. Wang X, Ouyang Y, Liu J, Zhu M, Zhao G, Bao W, et al. Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies. BMJ : British Medical Journal. 2014;349:g4490.
27. Aune D, Giovannucci E, Boffetta P, Fadnes LT, Keum N, Norat T, et al. Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-a systematic review and dose-response meta-analysis of prospective studies. International journal of epidemiology. 2017;46(3):1029-56.
28. He FJ, Nowson CA, MacGregor GA. Fruit and vegetable consumption and stroke: meta-analysis of cohort studies. Lancet. 2006;367(9507):320-6.
29. Liu RH. Whole grain phytochemicals and health. Journal of Cereal Science. 2007;46(3):207-19.