I lived on protein shakes for an entire week... here are the shocking effects it had on my mind and body READ MORE: Doctors reveal the dark truth about protein shakes By CASSIDY MORRISON SENIOR HEALTH REPORTER FOR DAILYMAIL.COM Published: 03:41 BST, 23 April 2025 | Updated: 04:15 BST, 23 April 2025 A fitness influencer who rocketed to stardom for his extreme food challenges called his latest endeavor ‘the worst week of my entire life.’ Michael Alves, who posts under the name Killdozer, embarked on a seven-day challenge in which he only consumed protein shakes; no solid food, no water. Alves, from San Diego, is towering at 6’5” and works out daily. Comments on his video detailing the challenge pointed out that, given his body size and level of activity, his daily calorie and vitamin intake were low to the point of being dangerous. It accomplished the goal he set at the start of the week, though. Having just returned from Japan, where he gained about seven pounds, Alves set out to shed some weight. He did, in fact, lose 17 pounds that week. He said: ‘I guess mission accomplished, we lost a bunch of weight, but the main problem is we almost passed out. From day three to day seven, it was headaches and stomach aches almost constantly.’ The calorie content of each protein shake ranged from 150 to 400. He drank an average of five to seven shakes daily. Having just returned from Japan , where he gained about seven pounds, Alves set out to shed some weight. He did, in fact, lose 17 pounds that week Alves acknowledged, while in a grocery store, the camera showing a row of about five shakes in his shopping basket, that, ‘calorically speaking, this is really not enough for one day.’ Throughout the seven days, he described days-long constipation, the feeling of daggers in his stomach, and ‘constant agony.’ Cancer-causing ingredients found in popular protein powders ‘The protein shake challenge is going to get a one out of 10,’ he said. ‘If for some reason you ever plan on doing some of these challenges, don't do this one, please.’ Alves filled his shopping cart with protein shakes every day, with the brands he liked – Fair Life, MRE Blueberry Cobbler – and those he did not – Premier Protein and Bold House Farms. He said on day one: ‘I'm really wondering if I'm going to start missing solid foods... I think I'm going to be good for seven days.’ The Recommended Dietary Allowance (RDA) for protein is a modest 0.8 grams of protein per kilogram of body weight, or 0.36 grams per pound. A very active 6'5" man weighing 261.6 lbs (his weight at the start of the challenge), should aim to consume about 4,500 calories including 95 grams of protein per day. Alves was drinking between 150g and 280g daily. Alves stocked up daily on protein shakes—favorites like Fairlife and MRE Blueberry Cobbler, and less-liked brands like Premier Protein. As a 6'5", 261-pound active man, he needed ~4,500 calories (95g protein) daily—but downed 150–280g of protein from shakes alone The first two days lulled him into the sense that the coming week would be a painless experiment. But more than a dozen shakes in on day three, without changing his gym habits, Alves began sensing a severe disturbance in his body. On the morning of day three, he said: ‘I spent 2 hours in the bathroom. Something is going on in my stomach area, and I don't know what.’ He began experiencing severe muscle cramps, with his foot stuck in a perpetual arch and unable to relax. ‘Maybe there was some sort of chemical reaction with the protein shakes in the freezer? I don’t know,’ he said. ‘To be honest, the worst I felt in any food challenge I've done so far was today.’ The severe stomach pain and cramping continued throughout the week. The next day, he confessed at 2:30 in the morning that, for the past two days, ‘my stomach has been in constant pain,’ adding that he had a severe headache. Alves tried to drink only pre-packaged protein shakes, but supplemented with a powder at certain points to improve the flavor of the shakes He added that he believed he would have to go to the hospital. Some commenters noted about his wife, Jessica, ‘being a nurse just makes sense,’ and said, ‘It's good to know that he has a medical professional nearby for these challenges.’ He spent between two and three unproductive hours on the toilet that night, adding: ‘Aside from the time in college when I broke my back, this is probably one of the most painful experiences I’ve ever had.’ For seven days, except having to drink some water at the gym when he thought he was going to faint – ‘I’m not proud of it but I had to I feel like an absolute failure’ – Alves went without water, whole foods with fiber and vitamins, and had an excess amount of protein, leading to constipation, overworked kidneys, gut irritation, and an electrolyte imbalance. Protein shakes are supplements, not meant to replace all food. Many of them contain high amounts of sweeteners like sucralose and aspartame, which can trigger irritable bowel syndrome-like symptoms, as well as sugar alcohols like sorbitol, which can cause diarrhea. They lack the essential nutrients found in whole fruits, vegetables, and healthy fats, leading to fatigue and headaches. While he dropped an impressive 17 lbs, bringing his weight to 244lbs, Alves noted in a before-and-after photo comparison that he looked ‘a lot weaker’ at the end of the challenge. Such a crash diet would result in rapid water loss and cause the body to break down muscle proteins for energy, making it an ineffective method for losing weight and maintaining it. Share or comment on this article: I lived on protein shakes for an entire week... here are the shocking effects it had on my mind and body Add comment