To think I am not going to whither away?

I eat 0 meat every day for high on 30 +years , and one look at me and you would see I am far from withering away ! 😂

Yes, i'm aware of these factors but meat and dairy consumption trump all of the above in terms of environmental impact. Reducing population intake is the single most effective action to take for reduction in environmental impact. It does seem counter intuitive in the case of non locally grown stuff. We need to eat more beans, we can grow them here.
Also scary reading about the uk's food insecurity....more beans is thecanswer to everything!

I've read the evidence base and i can categorically say that meat eaters only travel by horseback, which is definitely better for the planet, the horses enjoy it and it makes them feel all posh and superior.

Nice to hear one that is practicing what they preach - most unfortunately do not.
It's mainly a public performance, a desire to belong to a group or simply to feel superior to everyone else.

TheDaysAreGettingLongerAtLast I cannot speak for other vegans but as I am concerned about the planet I "ration" my overseas travel to once every 10 or 12 years. I also walk or cycle whenever possible and only use the car if it is really necessary. Buses and trains are frequently more efficient.

Please do not label all "middle class vegans" as hypocrites. I don't preach either FYI.

I'm lugging around about 55kg of muscle (according to some probably inaccurate Tanita readings) and I eat meat less than that and fish very infrequently.

Defo walk and lift or at least get up and down off the floor frequently.

The thing that gets me the most with middle-class vegans is their overarching hypocrisy. Their carbon footprint is usually far greater than the people they preach at. How many vegans forgo plane travel, foreign holidays, or all the technological conveniences of modern life? One on MN manage to combine bragging about her big house, fancy electric gates while simultaneously preaching about meat and climate change...

The fact that meat production is bad for the environment does not automatically mean that vegan diets will solve the issue. How much of your plant based diet is grown locally and sustainably, and how much is shipped from around the world? Some common vegan products have a disproportionate environmental footprint, nut milks being an obvious one. It isnt as simple as just eating plant based. Eating locally produced food, and eating what's is season, is a key factor and that may well include some meat and fish rather than eating perishable foods flown halfway across the world.

@TheDaysAreGettingLongerAtLast and there we have it. Individual entitlement will obscure any moral discourse or progress.
Eating steak alone won't build muscle. You have to lift the weights whichever protein you put in to power them. With the added delights of increased colorectal cancer risk.
I loved eating steak by the way; it became unconscionable.

Edited for semi-colon, ironically!

If more humans adopted a vegan diet they would have a whole new raft of illnesses. Like most people, I'd rather eat a nice steak than eat plants and then have to do weight-lifting to compensate.

Yes anaemia is extremely prevalent. Some populations eat more dairy etc to compensate. 60% of India is not vegetarian.

I think protein needs go up as we age

https://lifestylemedicine.stanford.edu/protein-needs-for-adults-50/

Up to you obviously, but your BIL may not be wrong.

@TheDaysAreGettingLongerAtLast poverty in India is a different issue and of course poverty will impact on health outcomes
Plant based eating is good for humans when they have access to adequate food, and if more humans adopted it a whole raft of illnesses would be reduced.
Plants have calcium too, there are fewer cases of osteoprosis in Japan where dairy is typically not consumed, but tofu is.
Ref muscle wastage, advice for older women is to lift weights. Any protein will build muscle.
Your comment about social contagion I'll ignore because it's toxic.

The obesity crisis has been caused by sugar not meat.

Anyone truly concerned about climate change should stop all foreign travel, stop driving a car, get rid of their TV, electric shower, fridge, washing machine, dishwasher, laptop, smartphone, Xbox, live in a straw hut, wear hemp clothes, euthanize their pets and get sterilised.

Lots of people across the globe eat plant based diets because that's all they can afford or for irrational/religious reasons. As I mentioned previously 40% of children in India under the age of 5 - which is often cited as the exemplar of veganism - are stunted from lack of nutrition. I don't have the numbers who are also vegan but it is a common problem among children of parents who are vegan.

I'm calling out middle class western women because that is relevant to this country. Female vegans outnumber male vegans 2 to 1 in the UK alone.
1 in 4 vegans in the UK has an eating disorder and use veganism to mask this.

Young women are far more susceptible to social contagion than young men (also why they vastly outnumber young men when it comes to supporting trans rights).

Women are more likely to suffer from osteoporosis than men, especially those who have eating disorders or are vegan.

Following a balanced vegan diet that adequately compensates for not eating meat requires a lot of planning, time and funds. A lot of people following vegan diets are putting themselves at risk of osteoporosis, brain fog, muscle wasting and more.

@Birdsongisangry because the evidence base shows a global move to plant based eating is essential to prevent climate catastrophe, and in western countries, the ever growing obesity crisis. I'm not talking about individual experience, there will always be a minority of people who can't operate without animal based food, but structurally things need to change. I can't see it ever happening though because individualist entitlement and corporate gain will always prevail unfortunately.

I eat meat around twice a week and don't eat fish at all
Many people don't eat meat 3 times a day, in fact I doubt most do

Whether you eat meat or fish or not doesn’t matter. What matters is eating sufficient protein. Meat and fish is not the only source of protein.
You can get enough protein not eating meat or fish at all. I’m not vegetarian or vegan but I know this.

Track your meals for a week and calculate your average protein intake. It’s nice that your BIL cares enough to advise you to increase your protein levels as it’s something that could really help a lot of older women in particular.

@Knittedanimal why do you assume that you are right and everyone else's view is spurious and not based on any evidence?
I also have a strong interest in nutrition, have done for many years and have been vegan in the 90s, was veggie until my early thirties and have eaten meat for the last decade. I survived as a vegan, I put a hell of a lot of work into it, but I can't argue that I'm healthier now, even with far less time and energy to dedicate to it.
You're right that eating meat at the current level isn't sustainable, but also many advocates also acknowledge that veganism for everyone isn't sustainable too, at least not without significant change - there would be many compromises there too.

Another poster talked about b12 earlier. Meat eaters get it via injections to animals because industrial animsl farming has depleted soil. So we could all cut out the middleman and take a supplement. You'll notice that i included wholegrain rice with those lentils to ensure all 8 amino acids were included in the meal, along with vitamin c to aid iron absorbtion and readily available calcium in the spinach. I've spent 30 years having these sorts of discussions, and people have been conditioned for so long that eating animals is essential to their health that they forget to think critically. I've just been to a conference where the keynote was talking about the corporations who control global food networks and I quoted this thread in my question.
How can we address food related health issues when there is no proper education about nutrition/healthy eating & cooking at school level and in medical training, in the face of decades of societal conditioning by corporations?
People will clutch onto the spurious arguments we've seen above because they like the taste of animals and they've been led to believe it's necessary to do so, and acceptable.
The bottom line is, eating animals is unsustainable, unhealthy for us and the planet, an absolute horror show for 65 billion animals per year and morally unjustifiable.
As a species we absolutely must change the way we think about eating animals because the planet's health, and our own, depends on it.

Lentils do indeed have protein, but they're not a complete protein, as I'm sure you're aware. Just because many people around the world survive on vegetarian diets doesn't mean that they're nutritionally sound or that they aren't being affected by poor health.
I just did a quick Google and found some stats that got example in India, 30-40% of Indians generally eat a vegetarian diet. There's no information on malnutrition in that specific population, but around 47% of the overall population is thought to be B12 deficient.
It is entirely possible to have a balanced vegan or veggie diet as other posters have pointed out, but it does require having a varied diet and time to cook, and a certain level of wealth or privilege is needed for that.

I haven't eaten meat in over a decade and I'm going strong

Muscle loss and muscle wasting are 2 completely different things.

From what you have said, you are physically active, your diet has a balanced intake of plant and meat based protein, healthy fats, dairy and a variety of vegetables - sounds very much like a Mediterranean diet which is hyped to be the most healthy type of diet

The conditions he is referring to would give muscle wasting and is loss of muscle tissue through illness but under the circumstances you are in, I wouldn’t suggest you are high risk for these conditions. Muscle loss is a reduction in the size of the tissue however is rebuilt with activity and protein of which you do plenty

B12 can be gained from animal products but in your circumstances is fish, eggs and dairy - vegans of course usually need to take a supplement due to not having any intake of these at all

Frankly - he’s a bit full of something to make such a suggestion to you. Really can’t see his issue

TheDaysAreGettingLongerAtLast

What nonsense about vegans proselytizing. There are very many people who know me who have no idea I am vegan. Unless it crops up in a food situation such as a meal with friends I can't think of a reason to mention it. It's a personal choice, like the style of knickers I wear or which moisturiser I use, simply not interesting enough to talk about.

I meet a friend about once a month for tea and cake. We had been doing this for nearly two years before she noticed I always chose vegan cake. I prefer fruit teas so I hadn't been asking for oat milk.

What is worrying is that people stereotype vegans in the same way that they stereotype ethnicities or disabilities.