I need some help please.

I’m 40, female and 173cm tall

I used to be fit and active but over the last 8 years a combination of back problem, depression and insomnia mean things have slipped quite a bit.

I weighed in at 95kg 2 weeks ago, ideally I’d like to be 67kg or bit less. So I need to lose around 28kg. I’m vegetarian, cook from scratch and have a pretty good grasp on biology, nutrition etc.

I’ve had some success with fasting and keto diets in the past. So I started my diet with a 5 day fast to kick start ketosis.

I do blood tests for ketones and blood sugar each morning. By day 3 my ketone levels were >1.5 - the so called Optimum Ketosis zone. I ended my fast on day 5 and moved to a eating primarily fats and a bit of protein, making sure it was all v low carb. I continued intermittent fasting, eating just one very modest meal each evening.

By day 7 I’d lost 4kg, mostly glycogen and water weight I guess.

Days 8 and 9 there was no further weight loss, but my ketone levels were now >3 so I decided to switch to a low carb diet (<20g), still eating just once a day and also trying to restrict calories to 500-800.

I’ve been sticking to this religiously. Today is day 16 and I haven’t lost any further weight at all. I’m stuck at 91kg.

I understand weight loss sometimes stalls, but given I’m on a pretty strict regime, have lots of weight to lose and am just at the start of my diet I’m quite confused about what I’m getting wrong.

I had blood tests last March which checked my Thyroid etc and I am healthy. Since I started the diet I haven’t been doing any intensive exercise, but I have been keeping active - walking my dog, heavy gardening, helping a friend move house (actually that was quite intensive!)

I find this diet reasonably easy to stick to when I am seeing results, but I am getting really demoralised at the moment.

Ideas please...?

  • 19
    500-800 calories a day is really dangerous.
    – Eric
    Oct 17, 2017 at 15:44
  • I prefer working out. Do jogging or any cardio every day and watch also ur diet. I had my workouts together with my best drink for health.
    – user480873
    Oct 18, 2017 at 1:49
  • Unfortunately many programs don't consider the entirety of how the body works. It works on negative feedback loops, especially with hormones. You need to raise your leptin levels and your overall caloric intake (not by tons). The initial shock you've given your body created the initial change. Now your body has adjusted. Eat carbs for 3 days while upping your calories to closer to 1500 and then start over and do it (your process) again at at a slightly higher calorie intake. This will counteract the measures your body took to avoid loosing anymore weight. also be careful with acid levels.
    – BRogers
    Oct 18, 2017 at 2:28
  • Moderators? Moderators? Anyone there? I guess we allow weight loss questions that don't pertain to fitness as long as it's popular.
    – michael
    Oct 18, 2017 at 19:48
  • 2
    @michael, weight loss is on topic, but the cross over into nutrition that has nothing to do with weight loss or fitness is one of the lines for me. Weight management is core to physical fitness, but "is coffee good for me?" is an off topic nutrition item. My $0.02. fitness.meta.stackexchange.com/questions/226/…
    – Eric
    Oct 19, 2017 at 15:47

6 Answers 6


First of all eating under BMR may slow down your metabolism - that is the case we do not want. Some researches have shown that keto diet can cause some problems. If you push your body in a bad way, you will end up with some health problems.

Here are my recommendations that worked for me while burning fat and losing weight:

  1. Calculate your TDEE and eat 300-500 less of it. You do not have to pay attention too much about what you eat. Since you are on deficit, your body will not store fat. Losing a lot of weight suddenly is unhealthy. The process will take time.

  2. Do exercise moderately. Moderate weightlifting is best to burn fat effectively. 2 or 3 times moderate full body workout and 1 or 2 times cardio like swimming is ok. Cardio should also be moderate.

  3. Eat enough carbs, fat and protein. Do not be afraid of carbs. Carbs do not make you fat, caloric surplus does. Eat good carbs and do not limit how much carbs you eat. Have balanced meals.

  4. Stay away from garbage food as much as possible.

  5. Drink enough water and sleep enough.

At the beginning you can gain a few pounds since you will increase your carb intake. Do not worry about it.

Before doing anything consult several doctors.

Edit: If you are going to increase your caloric intake, do it gradually.

For any question feel free to ask.

  • 3
    Got there before I did. Whenever I have a female talk to me and say "I don't understand why my weight loss has stalled, I'm only eating 800 calories..." I always want to face palm. As an addendum though, if someone's been eating low calories for a while, they need to build up slowly, not just suddenly gorge themselves, otherwise they can seriously stress their digestive system as well as metabolism
    – Dark Hippo
    Oct 17, 2017 at 13:08
  • Neither of these studies prove much, food and diet research is notoriously multi variate - through careful or careless p-hacking you can prove that anything is either beneficial or harmful. If you take a step back, to the thermodynamic side, we know that the human body requires energy, and will use whatever is available. If you eat 800 calories, you are losing alot of fat. However, we also know that starving affects your mental state and general health and for that reason alone one should avoid starvation in summary; while research is not helpful, the advice is still good.
    – Stian
    Oct 17, 2017 at 17:05
  • @StianYttervik I agree, which is why I tend to lean towards anecdotal, or "in the trenches" advice over scientific studies. Someone comes to me with nutrition questions, I'll make suggestions based on experience (both mine and others), if they don't work, I'll suggest something else. I know some people stick religiously to the science, and if something doesn't work, they immediately assume that the issue is with the implementation, not the act itself (i.e. you're not counting calories, you're not recording enough, you're cheating on your diet, etc, etc)
    – Dark Hippo
    Oct 18, 2017 at 7:43
  • @DarkHippo - While still not directly addressing the metabolic slowdown, there is a new calculator (That also busts the 3500 calorie myth) that takes into account metabolic changes with weight change. math heavy background pdf and article on calculators
    – JohnP
    Nov 15, 2017 at 21:26
  • Regarding increasing calories slowly: Layne Norton on Metabolic damage and reverse dieting: youtube.com/watch?v=EY1DsZMNfNw
    – Andy
    Oct 9, 2020 at 20:16

The most successful (pardon the pun) recipe I've seen for weight loss has the same basic ingredients:

Control your diet. I think you definitely have the discipline but 500-800 calories is generally pretty dangerous. I'm not being hyperbolic to state that your body will eventually die if you only consume that many calories, but you'll have plenty of serious health complications first to sound the alarms. There are some good calorie calculators out there that will tell you (a) how many calories you need to sustain your current body and (b) what kind of reductions you can think about with corresponding anticipated fat loss.

I reject the notion of "it doesn't matter what you eat", and I've seen vegetarians and vegans in particular quite guilty of having terrible macronutrient profiles but wrapping it up in a banner of "I'm eating vegetarian/vegan so therefore it's healthy."

Strength training. Several times over again, strength training (typically weight training) has shown to be more effective than "cardio" for fat loss. In short, your metabolism increases as muscle tissue is expensive to maintain from a caloric prospective.

Systemic positive health choices. To this I would put in treating any chronic health issues, getting sufficient sleep, and trying to move around rather than sit down throughout the day.

You mentioned that your current weight gain and fitness loss is over a roughly 8 year period. It took a while to get where you are, and it will take a while to get back from it. Fortunately it won't be 8 years though, I think reasonable in-the-mirror-changes can be expected within the first six months if you stick to it.

It's a whole lifestyle change, but arguably the most critical for any of us to make.


Let me share some things I've learned about good health and effective weight loss/control.

It's a long-term journey:

Good health (which includes a healthy body fat composition) is a lifelong journey. Don't get impatient or frustrated. It's great that you're looking for ideas and things to try, but remember that you are in this for the long haul, and two weeks is a short time. I haven't tried a ketogenic diet, but I eat a healthy vegetarian diet, and try to keep the carbs a little low, and the fats a little high. It doesn't sound like you are doing anything wrong, but subjectively speaking your approach sounds difficult and complicated. It'll take you months to get to where you want to go, and your strategy has to be something you can keep up for months. If keto works for you and is sustainable, go for it. If not I would suggest mixing intermittent fasting with "eat food, mostly vegetables, not too much" on your non-fasting days, combined with intermittent fasting.

Fasting is good for you

Don't believe anyone who tells you that fasting is unhealthy or dangerous. There is a large and growing body of evidence that fasting is both safe and effective, and has a large body of positive health benefits. If you are going to do longer fasts (over a week say), you may want to take a multivitamin and mineral supplements, but fasting has been a part of the human experience and human culture for millenia. Unless you are malnourished or have some complicating medical condition, fasting isn't just safe, it's good for you.

I recently completed a seven day fast which I intend to repeat years after reviewing the pretty compelling evidence that doing so dramatically reduces your chances of getting cancer. The evidence is growing that fasting reduces the probability of dementia and Alzheimers as well.

For an excellent survey of the health impacts of periodic fasting and its use for weight loss, I would strongly recommend "The Complete Guide to Fasting" by Jason Fung and Jimmy Moore. It's an extremely well researched and data grounded book, while still very approachable to the lay person. I found it informative and motivating. Dr Fung has a pretty large online presence and you might find it helpful to watch some of his videos.

Fasting isn't just an effective weight loss strategy, it's really healthy.

Listen to your body

Checking the scale regularly is a good way to measure progress, but it's not the only way, and it shouldn't be your only metric. How are you feeling? If you're in the middle of a fast it's normal to be hungry, and in the first couple of days of a fast it's common to be tired or irritable, but those shouldn't be chronic experiences. In my seven day fast I found the third day really hard, but the fifth through seventh days I felt great. I also notice my skin clear up and soften and my joint aches disappear, both of which were very pleasant surprises.

There are physiological reasons you plateau

There seems to be real tendency for the human body to attempt to maintain a "set-point weight". If your body is used to being 95 kg, it's going to have physiological responses which try to keep it at that weight.

Okay, so what does that mean about your frustration?

Well, you lost 4kg and now you're plateauing for a while... I have read that it's typical to shed excess water during a fast. In one 4 day fast, I lost a kg per day, and regained ~3.2 kg when I broke the fast. My seven day fast was similar: 3 days of 1kg per day weight loss, followed by .2 kg per day, and then regaining a couple kilos after breaking the fast.

When fasting you can expect to burn about 200g of fat a day, more or less depending on your metabolism and activity level. It's very likely that you're continuing to burn fat, but it doesn't show up on the scale because you're retaining more water. Feel free to experiment, but don't get discourages. If you lose 1/2 to 1 kg per week, you're doing great. You do have to keep it up though, so adjust your strategy to something you can maintain.

Based on the set-point weight effect, I set myself plateau goals. I maintain a pretty steady workout regime, and then vary the number of fasting days I do to either lose or maintain weight. So for example, this October I'll do 5 days of 21 hour fasting (and eat healthy on the weekends), expecting to lose a few hundred grams of fat each week. Then I'll try to maintain my new weight for a week or two with a number of fast days, and then I'll try the cycle again.

This is a bit of a personal philosophy, but when doing physical training, be it for strength or endurance, it's important to vary your workout, and it's important to plan recovery periods -- typical marathon training involves 3 weeks of training followed by a recovery week (where you still exercise, but less so you can recharge your batteries). Often a recover week helps you avoid or surpass a plateau. I don't see why it should be different for weight loss.

Last week I didn't lose any weight at all, but looking in the mirror and pinching my belly, and looking at the progress along my belt notches, I'm confident my body fat composition moved in the right direction. So while the scale is important, I'm not letting it be my only measure of progress.

If I'm not making my 2 kg goal per month goal that way, I'll try doing a couple 2-day fasts, or maybe another 4 or 7 day fast -- whatever is convenient.

Hopefully some of that helps you.


It does not look like what you are doing is wrong. General approach to problem solving: if what you are doing is not working, do something different.

1: I am curious whether you maintained your ketone levels after your switch on day 9. Did they stay high?

2: There is a difference in opinion in the literature as to whether one needs to count calories with a ketogenic diet. Currently you are, and what you are doing is not working. So try not counting calories. Eat when you are hungry (maintaining ketosis / very low carbs). Eat until you are full. Eat at regular times of day. It is not inherently wrong to eat until you are full and it will not be harder than what you are doing now. And it is different, and still a ketogenic diet.

  1. Review meds. Some medicines including some commonly prescribed to people with your problems can promote weight gain. Mirtazepine is one example - good for sleep, depression, pain and making you hungry. Review your meds and the side effects and then review them with your prescribing physician. DO NOT TAKE THIS TO MEAN GO COLD TURKEY ON YOUR MEDS.

  2. I suspect exogenous hormone changes (read birth control pill or the like) sabotage some women who are trying to lose weight. Certain progestins have prednisone-like side effects, for example. 40 is a time of life when some people change what they have been doing - stopping something they used to do, or starting something new. If you are one that uses exogenous hormones, consider going back to what you used 8 years ago before you picked up the weight.

  3. Consider exercise. Some people consider the presence of ketones to be commanding the body to use fats for fuel, as carbs are in short supply (and need to be reserved for synthetic functions). If you are actually eating until you are full you might find that you have a lot of energy. If you exercise during ketosis, calories you burn will be fat calories. The combination of exercise with ketosis can produce impressive weight loss.

  4. Physical therapy. If you are getting back into exercise it can be good to have guidance. If you have had medical attention for depression / back pain maybe you have been offered physical therapy. If not usually a request will yield a prescription. A nice thing about PT is that insurance will often pay. You can use your therapist like a personal trainer, guiding you to exercises that suit your body as it is now, and preventing you from hurting yourself.

Side note: I must say the idea of a vegetarian ketogenic diet is a little daunting to me. I am sure there is a literature about it. But even a handful of nuts was enough to break ketosis for me. No beans either. With no meat, fish, beans or nuts I don't know where you will get your protein. A lot of cheese, I guess. Maybe those synthetic soysages.


There are several factors to weight loss. It all depends on where you are starting, and what your target/goals are.

While calories count, hormones have a far larger influence in terms of what/when/how you absorb/use/store nutrition. Insulin levels and resistance are huge in this. As are other hormones like cortisol are also factors. Not to mention hunger/satiety hormones.

The most effective ways to influence these seems to be based around:

  1. Eating frequency
  2. Macro nutrient profile
  3. Caloric load

Eating Frequency

In terms of eating frequency, the old adage of eat many small meals may not be the best advice for weight loss. More recent research shows that eating fewer/larger meals is better for weight loss than more frequent eating. Specifically extending fasting periods (days at a time) works very well.

Every time you eat, you get hormone responses to process what you eat, this can have a huge effect. Also, hunger does not correlate so much with caloric need, it tends to be a circadian response to when you eat, and what you last ate.

Macro Nutrient Profile

If you are diabetic, you REALLY want to minimize your carbs. You can make up caloric need with additional fats. Protein needs are based around your lean body mass, and your weight lifting/workout profile.

Fat is not the enemy, you want about 0.5 - 1g of fat per gram of protein. This helps offset insulin response and keeps your macro profile in a great range.

Avoid sugars, when you have them, they should be part of whole fruit and nuts. If you are doing keto, then just don't have them... Under 5g of sugars a day should be your goal on keto. Alcohol sugars also affect different people differently, and depends heavily on your gut flora. Avoid them if you are stalling out, see how they effect you.

Other carbs, on keto, your total carbs (including fiber, hidden carbs, etc) should be well under 30-50g/day or around 5% of your daily calories. Your net carbs (total minus 1/2 alcohol sugars and fiber) should be under 20g/day. Absorption of fiber, alcohol sugars will vary by person. Also, there are fractions of carbs in everything, and they add up. If you aren't insulin resistant, you can have 100-200g carbs on a given day, but may want to minimize anything refined or starchy.

Alcohol, while alcohol doesn't count as a carb completely, you can think of it as a super carb in terms of calories and influence on your body. A little is fine, but should be no more than 4-8 servings a week if you can avoid it.

Hormone Response

In general carbs will cause insulin response. The breakdown of sugars goes into both unhealthy fats and glucose in the body and can cause insulin resistance alone. Other carbs will have a similar effect, but sugars are particularly bad and should be minimized.

Proteins also cause insulin response, but have a different profile breakdown, there are also other hormone responses that offset the insulin increase. Fats with protein seem to have the best response.

Caloric load

Calories still count... if you eat 5000g fat/day, you will gain some weight. It won't be the same as 5000g sugar/day, or even carbs/day. The macros have different effects, but in general, you want to target your minimal needs and fill up to your caloric load (BMR + exercise). If you are losing weight, target 75-85% of your caloric load on average, or have extended fasting between meals.

More on Fasting

As an aside, the effects of an extended water fast are a bit different than just a low calorie intake. Many use a ketogenic diet as a path to make fasting for extended periods (one meal a day, or less).


According to conventional wisdom (and some on this forum?) eating 800 kcal per day or less is crazy and dangerous.

However the credible Medical Doctor and BBC science journalist Michael Mosley is promoting exactly this with his "Fast 800 diet". As I understand it is based on a large study on reversing diabetes by restricting caloric intake done in the UK called DIRECT.

This may potentially be dangerous and I do not know which steps the NHS in UK and Michael Mosley are taking. Patients on the DIRECT study may e.g. have blood tests done frequently. Daily blood sugar and ketones measurement may be sufficient. This is not to be taken lightly and anyone starting such a diet will have to research this thoroughly and preferably clear it with their MD.

However from what I understand Michael Mosley is advocating a Mediterranean Diet both in general and also within the "Fast 800 diet". The Mediterranean Diet is low in carbs but high in both protein and unsaturated fat.

I would think that you will have a hard time getting both a decent amount of proteins and a low calory count on a vegetarian diet.

The current international Recommended Dietary Allowance (RDA) for protein is 0.8 g per kg of body weight (bw). Which should amount to 76 gram per day in your case. So you would have to eat e.g. 750 grams of tofu per day which nets 620 kcal. Which sounds like hard work and not very pleasant at all.

The same protein target could instead be achieved by e.g. 200 grams chicken and 1/2 l milk per day, which sounds more feasible and would only net 512 kcal. So you would have some room for e.g. olive oil with your salad.

The ketogenic diet on the other hand seem to be characterized by not counting calories and I would therefore think a higher daily caloric intake.

I cannot help wondering if you by combining two somewhat "extreme" diets have created a new bastarded potentially dangerous diet. Hope you know what you are doing and everything works out fine.

For a thorough (ca. 3 hrs) debate between a credible proponent of the ketogenic diet and a knowledgable critic I would recommend: Joe Rogan Experience #1176 - Dom D'Agostino & Layne Norton.

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