Daily Times

Scientists questioned how timing of food choices can affect your nutrition

Participants were asked to choose a post-workout snack before or after exercise

Likelihood of indulging in a brownie rose when the choice was after a workout

If you don’t want to threaten your hard work in the gym, choose your post-workout snack before, and not after.

Leaving the decision until after your workout can leave you more likely to indulge in chocolate as a reward, scientists claim.

A study found gym-goers who decide what to eat before they go on the treadmill are less likely to be swayed by chocolate afterwards.

The findings suggest that efforts to pre-plan food really do increase the odds of having a more nutritious diet.

Researchers at University of Nebraska – Lincoln, led by Professor Karsten Koehler, asked two groups of participants to go about their normal workout routines.

Before exercising, 137 members of one group decided whether they wanted an apple, brownie or no snack following the exercise session.

The 119 members of the other group were presented with the same choice after they had already exercised.

Roughly 74 per cent of participants who were asked prior to the workout session chose an apple, compared with 55 per cent of those asked afterward.

Whereas just 14 percent of the pre-exercise group selected the brownie, about 20 percent of the post-workout group decided to indulge.

Professor Koehler said: ‘If your goal is to lose weight, then I would say our findings support that you’re better off making the choice… not when you’re hungry after your workout, but instead before you go to the gym.’

The team’s recommendations support broader research looking at the relationship between timing and food choice.

Studies have consistently shown people are more willing to indulge when making immediate dietary decisions than when thinking ahead, said researcher Professor Christopher Gustafson.

‘Our study conformed very closely to the ideas in behavioral economics about this present-biased preference [for unhealthier options],’ Professor Gustafson said.

‘Using solely that model, I would’ve predicted that people would be more likely to choose the healthy snack when choosing before they exercise.’

The study, published in the journal Nutrients, also raised questions about how exercise can affect appetite.

One theory, known as compensatory eating, suggests that people consume more calorie-dense food in the aftermath of exercise to make up for calories lost.

But exercise-induced anorexia proposes that exercise can suppress appetite-related hormones and consequently lead people to eat less.

Professor Koehler said: ‘There have been a lot of lab studies that have looked at appetite and hunger.

‘Most of these studies have found that right after exercise, you seem to be less hungry.

‘I’ve always looked at these studies and wondered – does it have such a strong impact that you can use this window after you exercise to say, “Because I’m not hungry, I’m going to make a really good choice about what I eat”?

‘But knowing myself and many other exercisers, there’s also the notion that after you exercise, you want to reward yourself.’

There was evidence of both theories. The 12 per cent fraction that declined a snack entirely before doing their workout rose to 25 per cent in the post-workout group.

The six per cent increase in brownie choice between the pre- and post-exercise groups supported the compensatory eating theory.

But the researchers questioned – did the post-exercise group choose the brownie because of compensatory eating, or from the impulsive decision.

The team are conducting more research to figure out how and why people make food choices around exercise.

Published in Daily Times, February 3^rd 2019.