1. Protein — how much you really need
Of every macronutrient, protein has the most settled science. Protein provides the amino acids your body uses to build and repair muscle, manufacture hormones and enzymes, and maintain immune function. It also has the highest thermic effect of food (you burn 20–30% of its calories just digesting it) and produces the strongest satiety response of any macro Westerterp 2004.
The numbers
The old "Recommended Dietary Allowance" of 0.8 g/kg/day was set to prevent deficiency, not to support optimal health. For active adults, the modern evidence converges on a much higher range:
| Goal | Protein (g per kg body weight) | For a 70 kg / 154 lb adult |
|---|---|---|
| Sedentary baseline | 0.8 – 1.0 g/kg | 56 – 70 g |
| General fitness | 1.2 – 1.6 g/kg | 84 – 112 g |
| Building muscle | 1.6 – 2.2 g/kg | 112 – 154 g |
| Fat loss (preserve muscle) | 1.8 – 2.7 g/kg | 126 – 189 g |
| Adults 65+ | 1.2 – 1.5 g/kg minimum | 84 – 105 g |
The upper end of those ranges is supported by Morton et al.'s landmark 2018 systematic review and meta-analysis of 49 studies, which found gains plateau around 1.6 g/kg/day for muscle gain in most people Morton 2018. For older adults, higher intakes are increasingly recommended to fight sarcopenia (age-related muscle loss) Bauer 2013.
"You will not 'damage your kidneys' with high-protein diets if your kidneys are healthy. The opposite is far more dangerous: under-eating protein, especially as you age, accelerates the muscle loss that drives frailty and falls."Dr. Stuart Phillips — Professor of Kinesiology, McMaster University; one of the most-cited protein researchers in the world
Distribution matters
Your body can only use a finite amount of protein at one sitting for muscle protein synthesis — roughly 0.4 g/kg per meal, peaking around 30–40 g of high-quality protein Schoenfeld 2018. This means a 250 g chicken breast at dinner is largely "wasted" on muscle building if breakfast and lunch were protein-poor. Aim for 3–4 protein-anchored meals spread across the day.
2. Carbohydrates — friend, not foe
Despite the past two decades of low-carb marketing, carbohydrates remain the body's preferred fuel for high-intensity exercise. Glycogen — stored carbohydrate — powers anything above ~70% of your maximum heart rate. Run low and your training quality, mood, and sleep all suffer Burke 2017.
Daily carbohydrate ranges (per IOC/ACSM consensus)
- Light activity: 3–5 g/kg body weight
- Moderate (1 hr/day): 5–7 g/kg
- Endurance (1–3 hr/day): 6–10 g/kg
- Extreme (4+ hr/day): 8–12 g/kg
Quality > quantity
Most of your carbs should come from minimally processed sources: vegetables, fruit, whole grains, legumes, dairy. The fibre, micronutrients, and slow digestion that come along for the ride matter as much as the calories Reynolds 2019. Refined sugar isn't poison in modest amounts, but the dose makes the difference — and most North Americans are getting roughly 3× more than the WHO recommends WHO 2015.
Fibre — the underrated macro
Targets: ~25 g/day for women, ~38 g/day for men, per the Institute of Medicine. A 30-study meta-analysis published in The Lancet found people in the highest fibre-intake quintile had a 15–30% lower risk of all-cause mortality, cardiovascular disease, type 2 diabetes, and colorectal cancer compared with those eating the least Reynolds 2019.
3. Fats — the rehabilitation
The 1980s "fats are evil" message was based on flawed epidemiology. Decades of subsequent research have cleared most fats — and pinpointed the few that genuinely matter. Dietary fat supports hormone production (including testosterone), helps absorb fat-soluble vitamins (A, D, E, K), and provides essential fatty acids your body cannot manufacture.
What to eat more of
- Monounsaturated fats (olive oil, avocado, nuts) — the cornerstone of the Mediterranean pattern, with the strongest cardiovascular protective evidence we have Estruch 2018.
- Omega-3 polyunsaturated fats (fatty fish, flax, walnuts, chia) — evidence supports modest benefits for cardiovascular and cognitive health Aung 2018.
What to eat less of
- Industrial trans fats — the only food fat with a clear, dose-dependent harm signal. Now banned in many countries; check ingredient labels for "partially hydrogenated."
- Excess omega-6 from refined seed oils — not poison, but most North American diets skew badly toward omega-6, throwing off the omega-3:6 ratio implicated in chronic inflammation.
Total fat intake of 20–35% of calories is the long-standing IOM range and remains evidence-supported.
4. Meal timing & frequency
For decades fitness culture insisted you "must eat every 3 hours" or "must eat within 30 minutes of training." Both turn out to be largely wrong. The 2017 ISSN position stand on nutrient timing concluded the so-called "anabolic window" is actually closer to several hours, and total daily intake matters far more than precise meal timing Aragon & Schoenfeld 2013.
What the research actually shows
- Meal frequency (3 vs. 6 meals) shows no meaningful difference in body composition when calories and protein are matched Schoenfeld 2015.
- Distributing protein across 3–4 meals is slightly better than 1–2 mega-meals for muscle building.
- Pre-bed protein (20–40 g of casein or cottage cheese) modestly increases overnight muscle protein synthesis Trommelen 2016.
Intermittent fasting
Time-restricted eating (16:8 or similar) is not magic, but it is a legitimate tool for some people — especially those who struggle with calorie control across a long eating day. A 2022 NEJM trial of caloric restriction with vs. without time-restricted eating found no additional weight-loss benefit from the timing alone Liu 2022. The weight loss came from the calorie deficit; the schedule was just one way to create it.
Myth Buster
"Eating after 8 PM makes you fat."
The truth: Calories don't read the clock. Late-night eating only contributes to weight gain when it pushes you past your daily calorie target — which it often does, because evening hunger is psychologically triggered by stress and habit. Fix the trigger, not the time stamp.
5. Eating patterns that work
Here's the most important sentence in nutrition research: the best diet is the one you can actually keep doing. A landmark 2005 JAMA trial directly compared the Atkins, Zone, Ornish and Weight Watchers diets head-to-head and found adherence — not the diet itself — was the only meaningful predictor of long-term success Dansinger 2005.
The Mediterranean pattern
The single most evidence-supported eating pattern in the world. The PREDIMED trial — a five-year, 7,447-person randomized controlled trial published in NEJM — found a Mediterranean diet supplemented with olive oil or nuts reduced major cardiovascular events by approximately 30% versus a low-fat control diet Estruch 2018. Subsequent analyses have linked the same pattern with reduced risk of type 2 diabetes, cognitive decline, and several cancers.
Core principles: Vegetables and fruit at every meal, olive oil as primary fat, fish 2+ times per week, legumes, nuts, whole grains, modest dairy, modest red wine if consumed, sparing red meat, sparing added sugar.
Plant-forward (not necessarily plant-only)
You don't have to be vegan to capture most of the benefits. Studies show even partial substitution of plant-based protein for animal protein produces measurable cardiovascular and longevity benefits — without the all-or-nothing mental load Naghshi 2020.
6. Pre & post-workout fuel
Pre-workout (1–3 hours before)
Aim for a meal with ~0.5 g/kg of carbs, ~0.3 g/kg of protein, low fat and fibre (which slow digestion). Examples: oatmeal with banana and protein powder, chicken with rice and a bit of fruit, or Greek yogurt with berries.
If you can only fuel 30 min before training, choose simple carbs in liquid form (a small smoothie, some fruit) — your gut will thank you.
During-workout (only if > 60 min of intense work)
For most one-hour Beachside classes, you don't need to eat during. For long Hyrox training sessions, 30–60 g of carbs per hour from a sports drink or energy gel is the upper-range recommendation Jeukendrup 2014.
Post-workout
Eat a normal meal within a few hours containing 20–40 g of protein and quality carbs. The "30-minute window" is real but generous — the actual MPS-elevation period extends at least 4–6 hours post-training Aragon & Schoenfeld 2013. Don't stress the clock.
7. Supplements that have evidence
The supplement industry is largely unregulated theatre. The list of products with actual peer-reviewed performance evidence is short — but the ones that do have data have a lot of it.
| Supplement | Evidence | Typical Dose |
|---|---|---|
| Creatine monohydrate | Hundreds of RCTs. Improves strength, power, lean mass, and possibly cognition. Safe across decades of use. | 3–5 g/day, any time |
| Caffeine | Strong ergogenic effect on endurance, strength, and reaction time. Grgic 2020 | 3–6 mg/kg, 30–60 min pre |
| Whey/casein protein | Convenient way to hit protein targets. Whey post-workout, casein before bed. | 20–40 g per serving |
| Vitamin D₃ | Wide deficiency in northern populations (incl. Ontario). Supplementation generally recommended Oct–April. | 1000–2000 IU/day, individualized |
| Omega-3 (EPA/DHA) | Modest cardiovascular and anti-inflammatory benefit. Aung 2018 | 1–3 g combined EPA+DHA/day |
Almost every other category — fat burners, pre-workouts beyond caffeine, BCAAs (if your diet has enough protein), most "testosterone boosters" — is poorly supported. Save your money.
8. Common myths debunked
"Carbs after 6 PM make you gain fat."
The truth: Body composition is governed by total daily calories vs. expenditure, not the time of intake. Many cultures eat their largest meal late at night with normal body weights.
"You need to drink a gallon of water a day."
The truth: Fluid needs depend on body size, climate, activity, and food water content. Use thirst + urine colour as your gauge. Read the hydration guide →
"Detoxes / juice cleanses 'remove toxins' from the body."
The truth: Your liver and kidneys do this 24/7 for free. There is no peer-reviewed evidence that any commercial cleanse improves clinical health markers. Klein 2015
"Eating fat makes you fat."
The truth: Eating excess calories makes you gain fat. Fat is a calorie-dense macronutrient (9 cal/g), but it's also highly satiating. The Mediterranean pattern is high in fat and is the most evidence-backed eating pattern in the world.
9. Practical meal planning
Now the part most blogs skip: how do you actually plan a week?
The 4-Step Beachside Method
- Set your protein target. Use the table above. Divide by 3–4 to get a per-meal goal.
- Build the plate. Each main meal: a palm of protein, two fists of vegetables, a cupped hand of carbs, a thumb of fats. (The "hand-portion" method has ~85% accuracy vs. measured calorie counting in field studies PN 2019.)
- Repeat boring meals. The single biggest predictor of dietary success is having 3–5 default meals you can make on autopilot. Decision fatigue is the enemy.
- Plan one prep block. Sunday afternoon: cook 4–5 protein servings, roast a tray of vegetables, cook a pot of grains. Now your weekday lunches assemble in 90 seconds.
The plate, visualised
Harvard's Healthy Eating Plate is a free, validated visual you can print and stick on the fridge. Half plate = vegetables and fruit; a quarter plate = whole grains; a quarter plate = healthy protein; healthy oils for cooking; water as the default beverage.
Beachside takeaway
- Hit your protein target (1.6–2.2 g/kg if active).
- Eat ~30 g of fibre per day from real plants.
- Anchor on the Mediterranean pattern.
- Boring repetition beats elaborate planning.
- Sustainability beats optimization. Always.
Want help personalising this? Our coaches will sit down with you and turn it into a plan that fits your kitchen, schedule and goals — at no extra charge for members. Mention "nutrition consult" when you book your tour.