Photography: Christopher Griffith

A small plastic pouch filled with dark brown, organic matter arrived at my doorstep today. No, I didn’t immediately bolt down the street in hot pursuit of some malicious teenagers. Instead, I took a closer look and found that the bag actually contained something else entirely: dead crickets. I knew Alex Drysdale, founder of Crik Nutrition, was eager for me to sample his flagship product. I just hadn’t expected it so soon – he’d shipped it overnight from his office in Winnipeg, Canada.

Drysdale, a former communications technician who quit his job in 2015 to cash in on the protein boom, swears that these tempting morsels “are loaded with nutrients because they’re made from whole, crushed-up cricket – you’re eating the exoskeleton and all the organs.” I try not to picture cricket guts when I open the pouch and take a whiff. Surprisingly, the smell is sweet and nutty.

Feeling brave, I shove a spoonful in my mouth. Compared with gritty and bitter whey and soy powder varieties, this stuff dissolves instantly on my tongue and tastes like almonds and honey.

Crik is just the latest form of protein I’ve eaten recently. The others include protein-infused granola, protein pancakes, high-protein Greek yogurts and a wide variety of powders – whey, soy, pea, hemp and now cricket.

The protein industry reaps about £8 billion annually worldwide, a figure that’s more than quadrupled since 2005. Some dismiss this as just another fleeting food fad, the result of a connection to a few popular high-protein diets such as Paleo. A few experts claim we’re eating too much protein. But, I’m happy to report, scientists who study protein insist otherwise.

For the record, the US Recommended Dietary Allowance (RDA) officially recommends just 0.36 grams of protein per pound of bodyweight (around 0.8g per kilogram), while the NHS suggests roughly the same amount – 0.75g per kilo.

“That’s designed for the average person to just exist – hang out, watch TV, do whatever,” says Dr Mike Nelson, an exercise physiologist and founder of Extreme Human Performance, a fitness coaching firm that advocates a high-protein diet. “But if you’re not the average person, and you’re exercising more intensely, you’re going to need more protein.”

At 160lb (72.7kg), the US RDA puts me at 58g a day, which is scarcely more than a pot of Greek yogurt at breakfast and a small chicken breast for lunch, with zero protein for dinner. But based on recent findings, nutrition scientists now advise at least 0.68g per pound (1.5g/kg) and up to 0.75g (1.65g/kg) if you’re doing intensive weight training – multiple days of the week – and want to bulk up fast.

That would put my recommended intake at 120g a day, divided into four servings, consumed roughly four hours apart. Dr Stuart Phillips, a professor of kinesiology at McMaster University in Canada, who studies how protein supports muscle growth, tells me that because I exercise five or six days a week, 110g a day should be ample. I bump up my intake accordingly, almost doubling it.

Two weeks later I’ve dropped 5lb (2.3kg)– most of it off my belly. I’m lifting more weight for chest and overhead presses. But the most profound change is in recovery. The throbbing quads and calves I’d suffer after long runs? Gone. And when I overload my muscles while lifting, the soreness lasts for hours instead of days.

Now I crave protein like a drug. I eat it in the morning and before bed. I eat everything from omelettes to salmon to pulverised insects that look like shit. And here’s the thing: I’ve never felt better.

When I convey my experience to Dr Robert Wolfe, one of the early pioneers in protein science and now director of the Centre for Translational Research in Ageing and Longevity at the University of Arkansas, he’s not surprised. “When you look at the research, it’s impossible not to be impressed with the benefits of a higher proportion of protein than the RDA in the diet,” he says. Eat more protein, he says, and “by and large, you’re going to be fitter. That’s the reality.”

What’s “enough” Protein – and what’s too much?

Despite everything we know about the connection between protein and muscle growth (protein effectively means the amino acids from foods that our bodies require to be healthy and strong but don’t produce), it wasn’t until very recently that scientists began to determine just how much protein we should be eating, what types (animal or plant), when (morning or evening) and how much.

“In the 1980s, we used to think that if you averaged out your recommended protein intake over a week, you were OK,” says Dr Nancy Rodriguez, a professor of nutritional studies at the University of Connecticut. “But fast-forward ten years or more, and we realised it wasn’t just about having protein every two or three days. You should be eating it every day, distributing it among meals and snacks.”

For decades, dietitians and trainers generally adhered to the RDA. But Dr Donald Layman, a professor of nutrition at the University of Illinois, suspected this number might be too low. Layman had been investigating how humans metabolised amino acids and whether there was a threshold amount required to trigger protein synthesis, the biological mechanism that creates muscle mass.

In 1999, Layman conducted experiments on rats and found that a specific amount of the essential amino acid leucine, contained in all protein, is necessary to kick-start synthesis. Leucine alone can’t create muscle – you need all nine essential amino acids to do that – but it’s the catalyst that ignites the process. “Until you get enough leucine, protein synthesis won’t run at 100%,” Layman explains.

When he extrapolated his data to humans, he determined that for someone like me to optimise post-workout muscle growth, I should be consuming at least 30g of protein per meal, which provides 2.5g of leucine. For that, a whey- or soy-based protein shake with half a pot of yogurt added would do the trick, as would a 110g T-bone steak.

But what happens if I eat more than that? Would devouring, say, 90g of protein in a single sitting (about 350g of salmon) triple muscle growth? No one knew the answer until Dr Doug Paddon-Jones, a professor of nutrition and metabolism at the University of Texas, consulted with Layman for a study.

In 2009, Paddon-Jones enlisted a group of volunteers, including eight men in their early 30s, all weighing about 175lb (80kg), and fed them each a 4oz (113g) steak which provided 30g of protein. Five hours later, he took blood samples and muscle biopsies from the volunteers. “There was a 50% improvement in muscle protein synthesis,” says Paddon-Jones.

When he repeated the test but ramped up the size of the meal, eventually tripling protein intake, synthesis remained the same. “That suggests that somewhere around 30g [per meal for an 80kg man] there is a ceiling effect for your ability to use protein-rich foods to build and repair muscle,” Paddon-Jones says.

That number will rise and fall proportionately: if you’re 105kg, for instance, your per-meal protein intake would rise to 40g. And there are other factors that can push that number even higher, such as genes. Granted, if you’re consuming more protein than that, there are still some added nutritional benefits – thanks to the amino acids and micronutrients in a varied protein diet (meat, legumes, seafood, soy) – but muscle protein synthesis falls off precipitously.

Too much protein in a single meal is like filling your car’s 60-litre tank with 100 litres of petrol: in the same way that much of the fuel would be wasted, spewing out onto the pavement, excess protein ends up in your urine. “You don’t have a storage site for protein,” explains Phillips. “You can’t pack it away for further use.”

Paddon-Jones says one major issue that you’ll rack up extra calories. “The biggest problem with overconsuming protein is you’re going to get fat. There’s an upper limit in terms of what your body can process at one time. You can eat more, but it’s not doing your muscles much good.”

Is one kind of protein better than another?

At the University of Connecticut, Rodriguez hones diets for pro athletes, including those in the NFL, NBA and NHL. She instructs them to get about 35g of protein per meal, scaling it up for heavier guys. But will any old protein do? Rodriguez cites several new studies that have examined plant versus animal proteins, and whole foods compared with supplements.

The upshot: to grow new muscle and get bigger while adhering to a low-calorie diet, whole, animal-based sources are preferable, specifically meat, poultry, fish, eggs and dairy.

In 2015 a World Health Organisation (WHO) report caused carnivores to panic because it labelled meat a carcinogen and lumped bacon with tobacco in the highest-risk category. Not to worry. First, the WHO study surveyed people who consumed heaps of meat every day. These folks are also often overweight and sedentary. So does meat give you cancer? Or do you get it from being fat and lazy? The answer is almost certainly the latter, meaning that if you’re fit and work out regularly, a modest serving (about 110g) a few times a week of beef, pork or even bacon isn’t going to put your health at risk.

“I don’t think you can become the best athlete you can be without meat,” says Dr Luc van Loon, an exercise physiology professor at Maastricht University in the Netherlands, adding that he favours whole animal foods like beef because they’re digested slowly – a steak can take 24 hours for the body to process – so it provides a steady protein supply all day.

If you’re a vegetarian or vegan, beans and tofu are acceptable alternatives. But remember: by proportion, animal meat packs up to three times as much protein as plant-based food like legumes and nuts. So with tofu, for example, you’ll have to eat a lot more of it to get the same protein you would dining on a hearty filet mignon or a three-egg cheese omelette. Some plant-based proteins are also high in carbohydrates, which, if not readily burned off, end up as fat. (Crickets are about 70% protein by weight.)

Unfortunately for vegetarians, the plant-based soy protein doesn’t build muscle as fast as animal protein or whey. “Soy is about 60% as effective as whey,” says Layman. “And if you use a small enough amount, say 12-15g, you will get no muscle-building effects.”

If you’re going the protein powder route, scientists suggest you choose whey, which is derived from cow’s milk. For a 2015 study in the Journal Of Food Science, Phillips analysed whey, soy and rice powders and found that whey had the highest leucine content of the three. “And when we’re talking about regenerating muscle, the key is protein higher in leucine,” he says. “Based on our work, whey tops the list.”

Whey also ranks first in its ability to feed muscles faster than any other protein type. “Whey protein is absorbed really quickly in the blood, within 15 to 20 minutes,” Paddon-Jones says. Train hard and your body burns stored carbs and fat to produce glucose for energy. But unlike fat, there’s no protein cache to tap for making muscle. And as Van Loon points out, “when you combine exercise with protein, you get a synergistic response – muscle protein synthesis is doubled.” That’s why experts love whey: its rapid absorption improves the rate of rebuilding compared with other protein sources.

Does it matter when I take protein?

Timing is everything. When muscles contract during strenuous exercise the cells become more anaerobic, and protein synthesis shuts off. So chugging a protein smoothie right before hitting the gym or while exercising is pointless – and a few studies suggest it may even be counterproductive, impeding your muscles’ ability to grow.

On the other hand, researchers have measured the largest gains in lean muscle growth in athletes who consume whey protein 30 to 90 minutes after training. “That’s when you get the biggest bang for your buck, because the machinery is set up to re-synthesise muscle,” Rodriguez says.

When we bulk up in response to resistance training, it’s because there’s a net gain of new muscle growth. Exercises break down your muscles, which respond by rebuilding themselves bigger and stronger – a process that protein amplifies. But like other scientists, Van Loon once believed this occurred only when we were awake.

Then a few years ago, he met with a few colleagues at a bar and “after too many beers,” as he puts it, “we thought, ‘What happens if we give people protein during sleep?’” Scientists had never considered whether protein could be metabolised at night or, if it could, whether muscle synthesis would occur.

When you eat protein, its amino acids are dispatched to various tissues – muscle, organ, bone – where they’re used to repair and rebuild cells. But to determine what happens at night, Van Loon had to pinpoint the exact where and when of this process.

So at a university animal research facility in the Netherlands, he rigged a Holstein cow with intravenous tubing and pumped in £30,000 worth of chemical compounds called tracers that allow scientists to follow them throughout the body. From the cow’s milk, Van Loon derived a protein supplement he could give to human test subjects and then track the amino acids throughout their bodies. “I could see the digestion and absorption, how much of the protein becomes available in the circulation, and how much of what you eat lands in the muscle over a few hours,” he explains.

Next he conducted two separate protein-and-sleep studies, recruiting healthy, active male subjects in their early 20s. In the first experiment, the men exercised in the evening, then half took a protein supplement before bedtime, with the remainder fed a placebo. Van Loon found that theprotein was effectively digested and absorbed while the men slept, and muscle rebuilding was also higher.

In the next study, he had the subjects lift weights for three months in the evenings, with half taking a protein supplement before bedtime and the other half a placebo. He found the group who consumed protein ahead of sleeping had a greater increase in muscle mass and strength.

Based on his initial results, Van Loon recommends a “fourth meal” of protein approximately 30 minutes before bedtime – that would be about 30g for a guy my size. But keep calories to a minimum, since you’re not going to burn them off while you sleep.

Good choices are Greek yogurt, cottage cheese or a protein smoothie, assuming you minimise the sugary fillers like berries and juice. “Protein prior to sleep gives you a greater window of opportunity to facilitate muscle reconditioning,” Van Loon says. “It turns out that night-time is an unused period when you can stimulate the adaptive response to exercise.”

How do I get all this protein in?

Because I’m a carnivore, to me more protein means more seafood, chicken, pork and beef. On top of ample salmon and bison – two of my favourite foods – during my investigation, I added Van Loon’s fourth bedtime “meal” as well as whey after workouts. And my food shopping costs went out of control.

To combat this, I decided to mix things up. A few times a week I now splurge on pricy seafood (often tuna or halibut, among the protein kings of fish), and for smoothies I go with organic, grass-fed whey or Crik powder – the tastiest of the supplements, but, at roughly £3 for a 32g serving of protein, the most expensive. Primarily, though, I rely on protein-packed basics like yogurt, eggs, peanut butter and cheese.

For breakfast, I do one pot of fat-free Greek yogurt blended with blueberry kefir, a tablespoon of peanut butter and a teaspoon of honey. I follow my late-morning workout with a whey smoothie, using the provided scoop to get the correct amount of protein, then sweeten it with whatever fruit I happen to have – and that’s lunch. Dinner varies, but the main dish is almost always a high-protein whole food, such as pork or salmon, and before bed I might snack on a bowl of cottage cheese topped with sliced chicken or turkey breast.

I also learn about one big protein no-no: booze. Both Phillips and Paddon-Jones recount a tale shared among protein geeks, which involves a team of Australian Rules football players. During the off-season they’d meet every Friday at a gym for weight training. Afterward, they’d go drinking at a nearby pub. “No one was getting stronger in the off-season,” Paddon-Jones says. A coach with a hunch about the booze changed their training to Tuesdays – a less convenient night to get the beers in – “and they put on a ton of muscle mass and strength. Alcohol was shutting down protein synthesis.”

In 2013 Phillips led the first ever experiment to test the theory. He gathered eight men ages 21 to 26 and put them through an exercise routine that included weightlifting, cycling and high-intensity interval training. After the workout, he gave them each 50g of protein over a four-hour period and then got them smashed. Over the subsequent eight hours, he took tissue biopsies from their quad muscles. The result: muscle-protein synthesis had dropped by 24% compared with his control group, who got protein but no booze.

“Eight vodkas definitely messed up their muscles’ ability to utilise protein,” he says. “Alcohol affects your ability to regenerate and repair muscle and get it ready for a subsequent workout. If you’re an athlete, regularly consuming more than one or two drinks a day is not recommended.”

Are there any risks to eating more protein?

After two weeks, not only have I lost weight – chiefly because protein makes me feel fuller, which keeps me from snacking, and because of protein’s thermic effects, so I actually burn calories while digesting it – I also feel great. But I do notice something else that’s come with my new diet: I’m always thirsty. As it turns out, protein is hygroscopic, which means it attracts water like a magnet attracts iron filings. “If you shift to high-protein, you should drink 50% more water than you were drinking before,” Layman advises. But this gets me wondering: besides dehydration, what other potential risks might protein pose?

Low-carb diets, like the Atkins, which became popular in the ’90s, preached all-you-can-eat protein. With Atkins, you can fill up on steak and eggs as long as you limit carbs – consume enough protein and you’ll be too stuffed to eat anything else. (In contrast, the Paleo diet rightly embraces protein for its superior nutritional value. It falls short, however, because it doesn’t prescribe how much protein to eat or when to eat it. It also rejects dairy – even Greek yogurt, which new research has identified as a superlative protein.)

At the height of the Atkins craze, reports of health problems surfaced, the most serious being kidney failure. I ask Phillips whether I should be concerned, and I’m told no. Because many of the Atkins dieters were overweight, he explains, they were also “verging on type 2 diabetes”, a disease that can include kidney dysfunction. “But as the circular logic went, the high protein caused the kidney failure in the first place, and there’s no evidence of that.”

The other myth is that high protein intake is bad for your bones. The theory used to be that protein-rich foods nudged your body’s pH balance toward higher acidity, and too much acid would leach minerals including calcium from bones and lead to osteoporosis.

But, says Rodriguez, “we’re realising that eating adequate protein, along with calcium, is good for your bones, not bad for them”. Current research indicates that protein in fact increases bone density by improving calorie absorption. In a 2008 study in the American Journal Of Clinical Nutrition, Layman wrote, “Higher-protein diets are associated with greater bone mass and fewer fractures when calcium intake is adequate.”

There’s still one question that can’t be overlooked: how will consuming 100g or more of protein every day for years on end impact long-term muscle health? “We can’t answer that quite yet,” Layman says. We do know men in their mid-40s will find that their muscles begin to shrink naturally. “As we get older, we’re less efficient at turning protein into muscle,” Layman says. This has led nutritionists to assume that older adults need less protein. Having documented what high protein intake does for younger men, scientists now challenge that assumption and plan to conduct longitudinal studies to track men and their muscles over a lifetime.

It would be good to know this – but the sudden jump in strength and recovery I experience after disregarding the RDA and doubling my protein intake is reason enough to encourage me to stick with it long-term. Bring on the crickets.

Your Protein Power Calculator

What, when and how much to eat, in four simple steps

Step 1: What types?

Mix it up: beef, pork, chicken, seafood, tofu, even hemp seed, which has more protein by weight than any other veggie source. Variety is not only more fun, it also feeds muscles with a good medley of micronutrients and amino acids. If you want the best value, opt for foods that rank highest by protein-to-weight ratio: that means lean beef, tuna, chicken breasts and whey.

Step 2: When?

There is a threshold for protein, which means your muscles can use it only in small batches, according to research. Let’s say your weight puts your ideal protein intake at 140g per day. You should divide your daily intake into four servings. That’s 35g per meal: breakfast, lunch, dinner and a fourth snack right before bed. Also – and this is important – at least one of these meals should immediately follow a workout (see Step 4).

Step 3: How much?

Disregard the NHS recommendations, which suggest 0.75g of protein per day, per kilo of bodyweight. At 75kg, for example, that’s 56.25g, roughly what you get from one large chicken breast. That’s not enough to support the protein synthesis you want. Increase it to at least 112.5g, or 1.5g per kg. If you’re in the gym frequently and trying to add bulk, up to 2g per kg of bodyweight is OK.

Step 4: Anything else?

At 90% protein, whey beats all other supplements – and even whole foods like steak and salmon – in protein density and fast digestion. So pairing a whey smoothie with a workout is a no-brainer. Mix 35-40g of powder with berries, banana, honey and milk, and have it 30-90 minutes after exercise. In this post-training window, your body sucks up protein like a sponge and converts it to new muscle almost twice as fast as other times.