The boring parts of a lifter’s diet: fibre, micronutrients and vegetables

A lifter's diet discussion is almost entirely about protein and total energy. Both matter. Neither explains why someone eating adequate protein in a reasonable surplus feels sluggish, sleeps badly and has poor digestion.

Fibre

Recommendations sit around thirty grams a day for adults in most guidelines, and the majority of people fall well short.

A diet built around chicken, rice, protein shakes and oats is frequently low in fibre, and the consequences are immediate — poor digestive comfort, irregularity, and worse satiety, which matters both when dieting and when trying to eat a large surplus.

Longer term, fibre intake is associated with better cardiovascular and metabolic outcomes and with gut microbiome diversity.

Practical sources: legumes, whole grains, vegetables, fruit with the skin, nuts and seeds. Legumes in particular are among the most fibre-dense foods available and are frequently absent from lifters' diets.

Increase gradually and with water. A sudden jump from ten to thirty-five grams produces a very uncomfortable few days.

The micronutrients most likely to be short

Vitamin D. Deficiency is widespread, particularly at higher latitudes in winter and in people who train indoors. Associated with muscle function, bone health and immune function. Worth testing and correcting rather than guessing.

Iron. Common deficiency in menstruating women, in vegetarians and vegans, and in endurance athletes. Symptoms — fatigue, poor performance, breathlessness — are easily misattributed to overtraining. Test before supplementing; excess iron is harmful.

Magnesium. Intakes are frequently below recommendations. Involved in muscle function and energy metabolism. Green vegetables, nuts, seeds, whole grains and legumes are the main sources.

Calcium, particularly in people who avoid dairy, and particularly relevant for bone health alongside resistance training.

Vitamin B12, which is essentially absent from plant foods. Vegans need a supplement or fortified foods — this is not optional.

Iodine, often overlooked, and low in people who avoid dairy and iodised salt.

Zinc, lower in plant-based diets due to both intake and absorption.

Why deficiencies are easy to develop in a lifter's diet

Two patterns cause most of it.

Monotony. Eating the same six foods every day for meal-prep convenience means any nutrient absent from those six is absent from your diet entirely. Variety is the simplest insurance.

Energy restriction. Fewer calories means less food means fewer micronutrients. During a diet, micronutrient adequacy becomes harder precisely when the demand for recovery is high.

Vegetables and fruit, specifically

The reflex among people focused on macronutrients is to treat vegetables as an afterthought because they contribute little protein and few calories.

That is exactly backwards for someone dieting, where high-volume low-energy foods are the mechanism that makes a deficit tolerable. And for someone gaining, fruit is a straightforward and pleasant source of carbohydrate with micronutrients attached.

Aim for variety of colour, which is a crude but effective proxy for variety of micronutrients. Frozen is nutritionally comparable to fresh and considerably cheaper and more convenient.

Multivitamins

A reasonable insurance policy and not a substitute for food.

The evidence for multivitamins improving outcomes in well-fed people is weak. In someone eating a restricted or monotonous diet, or in a prolonged deficit, they are a cheap hedge against a gap.

What is better: identify likely gaps from your actual diet, test where appropriate, and address specifics. Supplementing what you are short of works; supplementing everything at low doses does not do much.

Salt, and the thing people get backwards

General population advice is to reduce sodium, and for most people that is sound. Someone training hard and sweating heavily is a different case — sodium losses in sweat are substantial, and people on very clean diets built from unprocessed foods sometimes end up genuinely low.

The symptoms of that are vague and easily misattributed: lightheadedness on standing, cramping, poor performance in the heat, and a general flatness. If you sweat heavily, eat mostly home-cooked whole foods and feel like this, adding salt to your food is a reasonable and free experiment.

This is not a licence to ignore cardiovascular advice, particularly with high blood pressure. It is a note that the population-level recommendation was not written with a heavy sweater in mind.

The practical checklist

Eat vegetables at two meals a day. Eat some fruit. Include legumes or whole grains most days. Vary your protein sources rather than eating chicken breast exclusively. Include some oily fish or an omega-3 source. Get some sunlight, or supplement vitamin D in winter.

None of this is exciting and none of it will appear in a training article about set volume. It is, however, the difference between feeling reasonable and feeling flat, and feeling flat is what people usually try to fix with supplements and programme changes.