The Fast 800: How to combine rapid weight loss and intermittent fasting for long-term health

I bought this book in 2023 and read the first part of it and thought it was just too hard, to restrictive, too everything and tucked it away on my bookshelf. So here i am taking another look. Jan. 1 2025 I was up in weight again so I started doing a 1000cal/day diet of my own and lost 7 pounds in the first week. Second week nothing. So I got this book off the shelf and wiped the dust off and read it again and started the 800 cal/day regimen. Three more lbs down as of today 1/26/25. I'm older so I'm fine with 1-1.5 lbs a week as I have a slow metabolism. It keeps me accountable with some structure and it works with a daily 30-45 min walk. I do mostly low carb and count only protein and calories and aim for 65-70g of protein minimum per day. It's worth a try if you're determined.

I love this book. About 10 plus pages are dedicated to correctly designed diet studies going on in UK and around the world. If you are in the USA it will make you feel like your government is slacking. Don’t even bother to do the regimen 8 weeks straight, just do it every third day. People are losing significant weight and keeping it off. People are reversing blood sugar issues. They write that Studies show there is no slow down of metabolism when doing “spurts” of dieting. I am Middle Age and nothing was working. Also, I was so close to a normal BMI, only having maybe 10 pounds to lose, I thought that’s why nothing was working. I do this regimen every third day. In other words, I eat 800 kcal one day and eat regular ( I.e. just to maintain weight) the next two days. It works like clockwork. The first day, first meal was a shock but easy after that. I do Slimfast (7 grams) keto coffee with light cream, small. Later is bell pepper and onion sautéed with 2-3 pieces of lunch meat and 5 second squirt of coconut PAM. Snack can be egg drop soup or small Kind bar. Lunch can be lettuce wraps, e.g. lettuce, one slice of cheese divided, 2-3 more slices of lunch meat, 1 teaspoon mayonnaise, misc veg like tomato, cucumber, onion inside the wraps. I use a good three slices of lettuce. At night I have about two hundred calories of meat and more vegetable. I’ve learned to enjoy salad with a about a third of an orange squeezed over it and add apple cider vinegar. I often get in about 40 calories of fat free yogurt and add a couple big strawberries or same volume of other berries. The weight lose is so predictable that it only took me one day to realize I no longer want to gorge on my regular days. For example, on my “regular” day I enjoyed breakfast with a frappe from the coffee shop but took my own mini kind bar instead of buying a pastry. The next “regular” day I did buy fast food chicken nuggets but hauled along yogurt, berries, and salad to round the meal off instead of buying fries and a huge burger. I do still very occasionally enjoy a Happy meal cheese burger on my regular days if I really want to go wild. You get so used to weight loss the morning after your 800 kcal day that you are extremely motivated to go for “maintenance” not “gorging” on the regular days- although you could. My whole world changed after three days. I cleaned my refrigerator out, gladly. I know exactly what I want and need from the grocery and nothing else. My smaller clothes are fitting. My scale is my friend. The only pain in the butt was the very first night. I planned all my next day’s food and wrote out all the calories. It was so worth it because I Picked my favorite healthy vegetable, protein, fats and I just tweak as needed or desired. Why 800kcal? The body is merely tortured with 1200 per day, because it’s not cutting back enough to shut the fat storing insulin down. In other words, insulin is a bit more like an on/off switch not a dimmer switch. Shutting it down allows the body to truly burn its own fat. you always know you can eat “maintenance” the next day so between that knowledge and the knowledge that weight loss is a sure thing you will be successful. Life changing. Check in with your doctor especially if you are on diabetes medication, blood pressure medication, and if you have any other usual conditions. Always good to check anyway. Some drugs have to be cut back on immediately, only your doctor knows for s rue. The book is Mediterranean not low carb, so enjoy your healthy non starchy carbs. I don’t do pasta or bread or potatoes on my diet days, but on my maintenance days I eat them in moderation. You can do this without intruding on your social life.go for it!

I enjoy the science behind the plan and thus enjoy reading about it. For me understanding the background helps me to "do it". The book itself offers enough information to start, without needing to buy additional (recipe) books. Although if you have a lot of weight to loose I can understand the need to vary your weekly menu. The information is clear. No matter what anyone tells you, dieting will never be easy. And when you go back to your old ways, you will gain back the weight in the end. Changing your diet on the long term is also not easy. Before you start you need to be sure you want to do it. As dr Mosley points out, it is not just willpower. And yes eating satisfying foods help and so does TRE. But you need to sure you are willing to put the work in. And to understand it is a lifechange.. you are not done after 8 to 12 weeks and you can't simply go back to your old ways... As said I enjoyed the book and the explanations. What I found lacking, is that there is no substitution mentioned for ingredients you can't/won't eat. I would not have considered myself a fussy eater, but trying to follow the recipes I actually feel I am a fussy eater. I hate avocado, coconut and most fish. I tolerate chicken and spinach, but I do not want to eat it often... Although I get that the current way of eating is the reason why I am seriously overweight, and that adjustment is needed, somethings are a no go. Stop drinking soda's with sweetners, sure.. Reducing the amount of (simple)carbs, check.. Eating more greens, make better choices in fruit (some have a very high natural sugar content) I get it. Trying out some new "stuff", oke! But for us "fussy" eaters why not add a note with substitutes? Also as some reviewers complain about the cost of the ingredients and the waste.. a weekmenu which uses the same ingredients so you can use them up would be a good addition. In overal a good informative book to read and use. Thank you, dr Mosley, for busting some dietmyths (such as fasting is bad for you) and bringing us factual proof and science on how our bodies work and how we can get healthier!

I have been working on reducing my weight ever since kindergarten, it seems, with limited success. It was a sad story of my life until I bought this book. A friend recommended the Dr. Mosley's method and we decided to try it, both I and my husband. We are in our 60s and gained a lot of shelter-in-place weight that we wanted to shed. The book offers a clear path to success and provides guidelines and recipes that are very easy to follow. I lost 15 lbs in the first 3 weeks, my husband also lost 15 lbs but in 2 weeks. We are continuing the diet and recommend this book to others.

The supporting info for the Fast800 diet is very informative and inspiring. However, the print version is very British, needs to be converted to American measurements and terminology. Having to constantly look up terms and convert measurements and oven temps. Who knew courgettes were zucchini? Or mange tout were thin green beans or sugar snap peas?

Sorry I don't have before and after because I'm not at the "after" stage yet, but I have lost 11 pounds so far. It is a very low calorie diet using the Mediterranean diet prototype. The author gives easy to understand background, instructions, and provides references. I'm someone who has a very difficult time losing weight and I really just needed "permission" to go this low. His recipes are geared to the UK so not really suitable for my American tastes, but I just follow the principles of the plan and have done fine.

Than this is the diet for you. I am 66 years old and literally was trying to lose 20 pounds for 10 years or more. I would drop five or six pounds and put it back on. I did Keto (gained weight on this and felt miserable), Weight Watchers, BistroMD, Nutrisystem, and too many to mention. Also did Intermittent fasting, which did help, but I didn’t see real, substantial results until I combined it with 800 calories a day. Strangely enough, I didn’t find it that difficult to do. I lost 10 pounds in about two weeks, and have kept it off. I’ve done a lot of traveling lately and now I feel if I did gain some of it back, I know how to get it off. And I haven’t tried the recipes, I just make up my own meal plans. I am about 56 and weighed 157 pounds. Now I’m down to about 143lbs. This diet really really works. Maybe a lot of the diets out there work for younger people, with a lot of weight to lose. But at my age, and with a much slower metabolism, the weight seemed nearly impossible to take-off until I tried this plan. If you’ve struggled with every diet on the planet, and nothing has worked, I strongly suggest you give us plan a try. It is so worth it.

If you can actually change your eating habits and follow this eating plan you will loose weight and keep it off. I could only do it for 3 months then just wanted more. I other readers better luck. I did loose 25 pounds and my belly in those 3months

Great book with tons of tasty ideas. Perfect to help you with your weekly/ fortnightly meal plans and shopping list. Recipes are great snd fill you up without bring hungry.

Good

Prima quality boek

This is a truly wonderful book. It has changed the way I eat. It is simple and easy to follow.

I highly recommend the Mediterranean lifestyle fat weight loss; I did a lot of research before selecting and the Mediterranean method is a safe weight loss program and the key is reading the entire book first , it tells of the ins and outs of body function and then follow the 2week meal plan. The plan is well balanced and nutritious even on 800 calories, stick to the 2 month plan you feel invigorated, energized and healthy … then to maintain I suggest the authors Mediterranean Lifestyle cookbook easy recipes and delicious.