Sustaining it for decades

Surveys have consistently found that a substantial proportion of people who adopt vegetarian or vegan diets subsequently return to eating animal products.

The reported reasons are remarkably consistent, and most of them are addressable.

The reasons people stop

Health concerns, real or perceived. Feeling unwell, fatigue, digestive problems, or being told by others that the diet is inadequate.

Most of these have a specific and fixable cause — insufficient energy, insufficient protein, missing supplements, or a fibre adjustment period.

Social difficulty. Eating out, family occasions, travel, and the accumulated friction of being the person with requirements.

Convenience. Life becoming busier, and the diet requiring more planning than there is time for.

Cravings, which people report as diminishing over time and as returning under stress.

Cost, where the diet was built on expensive alternatives rather than on legumes.

Loss of the original motivation, or a change in circumstances.

Isolation, particularly where nobody else in the household or social group eats the same way.

What predicts sustaining it

The research on this is limited and the patterns reported are consistent.

Cooking competence. People who can cook a range of meals without a recipe sustain it. People who rely on recipes and specialist products do not.

This is the strongest practical predictor and the most addressable.

Multiple motivations. People with ethical, health and environmental reasons together sustain it better than those with one, since any single motivation can be undermined.

Social support. Someone else in the household, a friend, a community. Isolation is a strong predictor of stopping.

Gradual rather than abrupt transition, in some studies.

Flexibility about strictness, which sounds contradictory and is not. People who allow themselves practical flexibility — when travelling, at a family event, when ill — report sustaining it longer than those who treat any deviation as failure.

The practical measures

Learn to cook. Ten meals you can make without thinking. This does more for adherence than anything else.

Our article on dinner formulas covers the structures.

Get the nutrition right. Enough energy, enough protein, and the supplements. Feeling unwell is the commonest reason people stop, and it is nearly always fixable.

Build it on cheap food. Legumes and grains rather than alternatives, so cost does not become a pressure.

Make it socially easy. Cook for people, do not evangelise, bring something to gatherings, choose accommodating restaurants, and do not comment on what anyone else eats.

The social cost is the one people most underestimate and it is largely within your control.

Allow flexibility. Decide in advance where your lines are and where they are not, so that a difficult situation does not become a crisis.

Find other people, in person or otherwise. Isolation is corrosive.

The all-or-nothing trap

Worth addressing directly, because it causes more failure than anything else.

People who treat a single deviation as having broken something frequently abandon the whole thing.

The framing that sustains: this is a direction rather than a rule. Someone eating plant-based ninety percent of the time, for thirty years, achieves considerably more — on health, on environmental impact, on animal welfare — than someone strict for eighteen months who then stops.

Nothing about a meal at a wedding undoes anything.

The long-term nutritional picture

Over decades, the things that matter change slightly.

Keep testing. Every few years, and more often if circumstances change. Deficiencies develop slowly and silently.

Keep supplementing. B12 is for life, and the commonest failure is people stopping because they feel fine — which is precisely what depleting stores feel like.

Adjust with age. Protein requirements rise, absorption of B12 declines, calcium and vitamin D matter more, and appetite falls.

Adjust with circumstances. Pregnancy, illness, injury, high training loads and periods of stress all change requirements.

Watch the diet narrowing. Diets tend to contract over years toward a small number of familiar meals. Deliberately adding something new occasionally counteracts it.

What people who have done it for decades say

Consistently, three things.

That the food became the point rather than the restriction — they cook things they want to eat rather than substitutes for things they cannot.

That it stopped requiring effort after the first year or two.

And that the social side, not the nutrition, was the part that took longest to settle.

The honest closing point

This is a way of eating rather than a test.

If it is making you unwell, fix the nutrition. If it is making your life unmanageable, loosen it. If it stops suiting you, change it.

And if it works, it works for a very long time and requires almost no thought after the first year, which is the part nobody tells you at the start.

General information rather than individual advice. Consult a registered dietitian for guidance specific to your circumstances, and continue B12 supplementation indefinitely.